Lee in Tekken and Cassandra in Soul Calibur. I don't usually use any other characters in those games unless I'm messing around but I have my back-ups of Wang and Siegfried too, because you can't get by in a fighting game knowing the ins and outs of only one character.
In other games,
Zhou Yu (Dynasty Warriors)
Cork-hat, frying pan, poncho wearing Sackboy (Little Big Planet)
Yao Ming (NBA 2K10; I make him triple-double every game)
CT costume 1, T costume 4 (Counter-Strike 1.5)
Squall (Dissidia)
four blocks in a line (Tetris; always seems to do most of the scorin' :D)
