To be fair, Cronos owned it first!

My choices would have to be Nocturno Culto, Thomas Karlsson and Orlok of Countess.

A few, out of the many, that have remained special to me over the years:

Silenius
- like the measured incantations of a powerful, recently awakened god ... with a touch of wickedness due to the unexpected disturbance

Nattfursth of Sorhin
- manic, possessed, channeling something wild and frenzied
http://www.youtube.com/watch?v=CxUXYcR_AwQ

Marten Bjorkman from early Algaion
- impassioned utterances, issued with an uniqueness that cannot easily be duplicated ... his vocals sound like they are coming from the void, edges quivering with bent light
http://www.youtube.com/watch?v=vtf-i8QMw7E

Vital Berazouski from Drygva
- love the inflection and tone ... sounds like it could rip the bark off a tree

Aldrahn
- i have always really enjoyed his delivery
http://www.youtube.com/watch?v=T9I3WPKeka8

Martin Matzak of Torchure
- hell yes
http://www.youtube.com/watch?v=EQDOXKB8gpk

Varjoherra
- his delivery and enunciation works perfectly with the Finnish language
http://www.youtube.com/watch?v=_Wi4xJ4SDYI

Missing link for Vital Berazouski
http://www.youtube.com/watch?v=lx4z20KX1CE