I have followed MusiciansFriend's "Stupid deal of the day" for a while, and Amazon's Gold Box deals occasionally have something music-related. I know most sites have a clearance/closeout section and mark dozens of items as "on sale" - is anyone aware of other sites that do a single daily deal like these? A handful of daily deals on a larger/wider site like NewEgg is also good, but it's a lot less interesting to look through a couple pages of things that don't exactly seem like great deals.

The two mentioned above:
http://www.musiciansfriend.com/stupid/
http://www.amazon.com/gp/goldbox/

I've never came across any that actually had anything worth getting even on 'sale'

I got the gibson melody maker flying v from musicians friend for $299, on sale. Everywhere else I look it's $400-$500+. zzounds.com often has some good prices as well. I tend to just browse eBay, I've found most of my best deals on there.