Street Fighter 3: 3rd Strike. The technical side of SF was greatly improved with that one. I was actually challenged in that game for a while. I was relying on common characters to damn much. I picked Makoto and immediately beat the game.
Guilty Gear X. Capcom needs to take a page out of Sammy Studios' book and start using high-res sprites for their games.
Soul Calibur. Mitsurugi. I could rape anyone in three maneuvers.
The godfather of them all:
Street Fighter II. Me playing as Ken was enough to piss off all of my cousins. Me playing as Ryu made them want to fight me.