The venues I frequent most (and that play the most metal in the DC metro area) are already listed (Empire [Jaxx], Ram's Head) but here are a few others that have metal shows every now and then:

Washington, DC:

930 Club, http://www.930.com/
They have metal shows every now and then (for instance, GWAR is playing there in December). A medium sized venue, longstanding and well known in DC. Easy to access by metro. I don't remember much about the bar, merch or ticket prices though, as I haven't been there in a while.

Howard Theatre, http://thehowardtheatre.com/
A brand new venue near Howard University. Very clean and swanky inside (sparkling marble, spotless bathrooms). There are water fountains by the bathrooms, a major benefit. Seems to mostly play pop and hip-hop shows, but they have metal every now and then (saw Epica/Alestorm/Insomnium there last week). Medium sized with an upstairs balcony (wasn't open when I went though, so can't comment on the view). Tables and sit down dining at the back of the room. Easy to access from the green/yellow line on metro. Parking is very limited (street or a tiny parking lot).

I'm sure there are more underground venues in DC, but I don't know about them

Baltimore, MD:

Soundstage, http://www.baltimoresoundstage.com/
I can't recall if I've ever been here, but I know friends have gone to see metal shows there. Another sometimes venue, I think. They do host Noise in the Basement, a local hard rock and metal night on Monday nights, and part of MD Deathfest will be there.

Chesapeake, VA:

Roger's Sports Pub
http://www.facebook.com/pub.rogers
This venue is a bit small. They serve food and alcohol. A lot of local metal shows happen here, but a few nationally known bands have played there as well. Deceased and Obsidian Tongue have both played there within the past few weeks, and Hour of 13 is playing there next month. This is the preferred bar for local fans of true underground metal to both attend and play shows.

Virginia Beach, VA:

Geared Up Rock Bar
http://www.facebook.com/geareduprockbar
This venue isn't too bad. They serve alcohol, and have a killer "bar food" menu. (I had the wings after my band's last show. Highly recommended). I've played there 4 times since the summer. We've had the same sound guy every time, and he's damn good.

Shaka's
http://www.facebook.com/ShakasVirginiaBeach
This place has a few metal shows every now and then, but has other types of music, too. The sound there wasn't bad. It's a Hawaiian themed place. The crappy thing is, a lot of shows typically start at 7, and have to be done at 10:30 or something like that. Plus, you have to pay for parking. But I guess if you're looking to book a show, and are in a pinch....

Knoxville, TN

The Poison Lawn
http://www.facebook.com/PLawnKnox
This is basically a big house. There's a big room dedicated to shows, and I guess the back area is where the people live. There's a PA there, and the folks that live there are in a band themselves. It was a little small, but I had a blast playing there. I'm almost 100% certain they only do metal shows.

Chattanooga, TN

Ziggy's
http://www.facebook.com/pages/Ziggys-Underground-Music/
This is a somewhat small bar with a stage area in the back (in a separate room). I've attended one metal show there, and I've seen flyers for other metal shows there, too. If you play there, be sure to bring EVERYTHING you might need. They did have a small PA there, but had no microphones, claiming they were all stolen the night before. The guy that owned the bar was bragging about how he won $200 in the lottery the night before, but still wouldn't pay the bands a dime. I know another band that has played there a couple times, and said the experience was pretty good, so who knows. The place is attached to a liquor store as well. Very strange place: Severely outdated 70's shag carpet, and a lot of empty space on the shelves, but they have the basics of anything you need there.

Silver Spring, MD

El Caracol Bar
No Website. Address: 609 Sligo Ave, Silver Spring, MD 20910

Just outside Washington DC is El Caracol Bar, a latino pool hall. I guess they just move the pool tables to the side when shows come in. The place is dark, and a general dump. Drinks are expensive, but the food is AMAZING. Authentic Latino food. It seems like strange place to have metal shows, but the crowd there was NUTS! I saw Imprecation and Mortem (Peru) there a few months ago. Darkened Nocturn Slaughtercult played there this month, and next month, a festival containing Morbosidad, Black Witchery, Extermination Angel, Satanik Goat Ritual, and more will be taking place there.

San Antonio, TX

The Mineshaft
This place doesn't have a Website. Not one that's kept up to date like it should, at least. The address is:
902 N.E. Loop 410
San Antonio, TX 78209

A lot of local metal shows happen here. It's a very strange place. It's in the back of a restaurant called "The Magic Time Machine", where waiters and waitresses dress up like characters from popular movies and cartoons. But after the restaurant closes, the shows commence, and there is an entrance in the back (to get right to the venue part). I've been to a few shows here, and have always had a good time. Good bar selection.

Backstage Live
http://www.facebook.com/backstagelivesatx

A lot of bigger touring metal shows come through here: Morbid Angel/Dark Funeral just stopped thru, and this is also where the Rites of Darkness festival/fiasco was held last year. It's a very large place. Pretty reasonably priced bar, but unfortunately, they charge for parking.

The White Rabbit
www.facebook.com/WhiteRabbit210

I can't say much about this place. Last time I went there was to see Six Feet Under in 2005. But a lot of my friends who still live in San Antonio still go to this place. They have metal shows, and other kinds of music, too. One of those Rites of Darkness festivals was held at this place as well, although I wasn't able to attend.

Updated the first post, everything in the US is now properly formatted! Thanks to Shutdown for making it work. I'll update the database with all of the recently posted venues soon, thanks for contributing them.

Syracuse NY:

These venues also have hardcore/punk scenes and just generally showcase a lot of underground bands. This is also of course omitting the obvious huge places like the Landmark Theater, which is one of the few places here attractive for chart toppers. I've seen Primus an Joe Bonamassa play there, good stuff, but anyways, this is a list or metal shows, so I didn't really include that.

Some of the more established places that touring bands go to:

The Lost Horizon
http://www.thelosthorizon.com/
Legit venue. Bigger acts show up here as far as the underground goes. Revocation is coming Thursday!

The Westcott Theater
http://thewestcotttheater.com/
Really, just about any kind of act can come up here. Anywhere in the popular to underground spectrum. There's also a lot of crap. But there definitely have been metal bands here before. In recent memory I can think of GWAR but that's about it.

Station 58
http://station58.com/
Also barely metal, but the Kreator/Diamond Plate(?)/Swallow the Sun tour came here a few months ago. edit: ok, apparently I also missed Deicide and DRI. Shame, the were probably killer shows.


Now for the places that I like to frequent more often. Lots of local shit:

Badlands
http://badlandssyracuse.blogspot.com/
Now this was the place to be. Lots of great local acts all the time, punk, metal, indie, you name it. It was pretty bare bones too. You just get four walls and a door, and that meant that it was a great place to mosh. It was also pretty safe too: no booze, good crowd etc.... But if you check out the link for the place, you'll see that there are no scheduled shows, and it looks pretty barren. As a matter of fact, nobody knows what the future of Badlands is going to be like. I don't know exactly what happened, but word on the street is, when a piece of the ceiling fell down and hit someone at the Westcott Theater mentioned above, all these concert venues started getting audited, and required renovations. Some of the bigger ones could afford that, Badlands couldn't. Anyways, I thought it was worth mentioning because they're trying to do something about it, and who knows, maybe one day it will restore it's function as a concert venue.

Gorham Brothers Music
http://www.gorhambrothersmusic.com/
This has, for the most part, been the replacement for Badlands, at least for the time being, but I've loved the place since I first found out about it, way before Badlands closed. It's a little bigger, but you also can't really romp around because there's tons of expensive stuff for sale there... Still, there are some absolutely killer shows. Lots of punk and grindcore, experimental music, metal, you name it. Also, the guys who own the place are really friendly, and have great taste. Whenever I need to buy something equipment wise for my guitar or whatever, I head there first, and I try to make it to as many shows as I can. (Tough on a uni schedule and budget.)

Those are all the places I know of. I'm sure there are more that are so hip, I don't even know about them ... If you're from 'cuse, and I've spouted some bad info here, please let me know.

Edit: There is also Funk n' Waffles and Dinosaur BBQ. I have been to both places to at but never to see a show. Don't know if they're metal friendly.

Look at copenhell.dk....

Thanks! If you're interested in offering some information on the region beyond there, you are welcome to. I'll archive it and add it to the database, then ask our great Danes. In fact, I think I see the whites of Caerbannog's eyes now!

Massachusetts:

Silk City Taproom
21+
Metal/punk shows every Friday. Mostly locals, but they do try to bring in out of town bands for every show.
99 Main St., Florence, MA
https://www.facebook.com/Silkcitymusic?ref=ts&fref=ts

The Sinclair
Mostly 18+, hosts some all-ages shows and some 21+.
Mostly touring bands as far as I can tell (Hammers of Misfortune played there, and they're hosting Enslaved/Pallbearer/Ancient Wisdom in February).
52 Church St., Cambridge, MA
http://www.sinclaircambridge.com / https://www.facebook.com/SinclairCambridge

Also, The Black Moon Music Lounge is closing its doors soon. It can probably be taken off the list, unless new owners come in and keep the name (and continue to operate it as a venue).

Do you happen to know if the Arena at Harbor Yard, Bridgeport, CT still has metal shows? I have never actually been there for music, only for car shows/hockey games. I know Disturbed, Killswitch Engage. Chimaira, and Lacuna Coil played there a while back.

http://www.websterbankarena.com/HomePag ... 26700&KEY=

Looking through the website, it seems as if the only events booked through April are sports related. It would be very convenient for me if metal bands played there, because I live less than 10 minutes away.

Very surprised Illinois isn't up yet.

Illinois

The Empty Bottle
1035 North Western Avenue Chicago, IL 60622
21+
Great smaller venue that hosts local and smaller touring bands.

Cobra Lounge
21+
235 North Ashland Avenue Chicago, IL 60607

Every Friday is a local metal show, and they do plenty of other shows as well.

Reggies
17+
2109 S. State St., Chicago, IL 60616

Hosts most of the metal tours that come through. Good venue.

Ye Olde Town Inn
21+
18 West Busse Avenue Mount Prospect, IL 60056

Hosts almost exclusively metal and puck shows. Booking is run by Jim from Jungle Rot, who is a great guy. It's a good venue, but its location outside of the city steers many of the urban dwellers away.

Mojoe's
All Ages
22 West Cass Street, Joliet, IL 60432

If a tour isn't at Reggies, it is most likely here. It is located almost an hour outside of Chicago, which makes getting there a pain, but it is a decent venue.

Township
21+
2200 North California Avenue Chicago, IL 60647

Smaller bar/venue. I have not been there myself, though they do a ton of local shows and I have heard good things.

Ultra Lounge
21+
2169 North Milwaukee Avenue Chicago, IL 60647

One of my favorite places to play, much like the Empty Bottle and Cobra Lounge, they host local and smaller touring bands.

Canopy Club
All ages
708 South Goodwin Avenue Urbana, IL 61801

Located in Champaign-Urbana about 2 1/2 hours south of Chicago. It is a larger venue that hosts bigger shows. Usually it is more mainstream music given its location next to University of Illinois, though it hosted the now-defunct Central Illinois Metalfest.

Albion House
1719 W Albion, CHICAGO

House venue in the Rogers Park neighborhood of Chicago. They do everything from local shows to small touring bands that for whatever reason can't get a venue. This is a good bet for weekday gigs. Getting in contact with them is sometimes a little tough, but they are good dudes.

No metal there, an arena tour hits there every few years, Priest/Anthrax/Hatebreed in 2005 was the last before the tour you mentioned in 2009. Rush played there last year though, but concerts in general don't stop there often. Occasionally there will be a metal show at the Mohegan Sun arena, like the Megadeth/Motorhead tour (Rush this year too), but there are so few metal bands playing that size of venue in Connecticut that I wouldn't bother with them.

Missing a few places in Maryland.

Newer place where I saw Suffocation (which will also be the alternative location for MDF this year):
Baltimore Soundstage:
http://www.baltimoresoundstage.com/

Ramshead Live (Only a block from Baltimore Soundstage, in viewing distance):
http://www.ramsheadlive.com/

The Fillmore Silver Spring:
http://fillmoresilverspring.com/

I've been to all three of these places, and all of them are good, medium sized clubs (size ascending from smallest to biggest).

Also just found this place in Baltimore, MD:

Sidebar Tavern:
http://www.sidebartavern.com/news.html

Keene, NH - The Railroad Tavern: http://www.reverbnation.com/venue/therailroadtavern

They do local metal on Sat/Sun, plus have had some bigger acts play there in the past: Dying Fetus, Job For a Cowboy, Aborted, Origin, Decrepit Birth, Cattle Decapitation (x2), Rings of Saturn, Battlecross, Vektor, and Pilgrim. Most notably, they have two larger shows coming up -

Woe on 05/12 (http://www.wickedmusicshop.com/products ... -the-night)

Bloodletting North America 9 featuring Gorod, Inanimate Existence, Kamikabe, and Vale Of Pnath on 05/21 (http://www.wickedmusicshop.com/products ... e-of-pnath)

Key Club - West Hollywood, California closed on March 15. Just noticed that it's still on the list, that should be changed.

A lot of Maryland places have been suggested but not added to the OP :/

Here's one which I don't think has been mentioned, if it has, sorry for the repetition:

Sergio's Place
11324 Fern St, Silver Spring, MD 20902
http://www.sergiosplace.com/
A hole in the wall El Salvadorean restaurant that has small shows, mainly of Latin American black metal I think. I saw Possessor and Lich King there, and the next week they were having a huge black metal line-up headlined by Sorcery, but I couldn't make that show. Like someone was saying about the other Latino place, they literally push the tables aside and set up some speakers in a corner. The band was practically, sometimes literally, in the pit. It was pretty intense.

The Beaumont Club in KCMO has closed.