Well, I have a few, they're not in order...
1. Makarov from MW2,he has the creepiest yet coolest voice ever.
2. Soap from "Gun", fun to listen to and he lost two fingers, he's earned this.
3. Atlas from Bioshock, shame he was a fraud, that accent always gets me smiling.
4. Jack of Blades from Fable, sweet mask and just plain sweet, they should've brought him back.
5. Kane and Lynch, you can't pick just one of them, primarily because they're mercenaries.
6. Skorge from Gears of War 2, although he never says anything, he has a chainsaw staff!
7. Andrew Ryan from Bishock, a damn genius with a very interesting outlook on life.
8. Kefka from FFVI, I don't know much about him, he's just wacky though.
9. ME from Oblivion, Fallout 3, Mass Effect, and just about every other RPG.