Melvin: It was Hwoarang.
I think those of you who listed Killer Instinct as a favorite must not have played it in a long time, because it was fucking terrible. Fun characters, but the engine sucked massive ass. I'm also not a fan of Mortal Kombat, which also had a very unbalanced engine. Uppercuts could be abused like no one's business and Shao Khan was just ridiculously gay. Lots of faceless characters, too. Deadly Alliance was okay, but i was mostly just thrilled with the ability to use Scorpion in a game that had a more well-rounded and balanced fighting system.
I play lots of fighting games, so i have a lot of favorites. Short rundown, and my favorite character in each because you all care:
Marvel vs Capcom 2 - Ken/Thanos/Magneto
SNK vs Capcom 2: Chaos - Geese, Terry
Capcom vs SNK 2 - Geese, Iori
Samurai Shodown 4 - Ukyo, Zankuro
Last Blade 2 - Hibiki
Garou: Mark of the Wolves (this game is 100% perfect) - Rock Howard, nigga
King of Fighters 99, 2001 - Terry, Yamazaki, K'
Soul Calibur II - Mitsurugi, Nightmare, Voldo
Tekken 4, 5 - Fury, Kazuya, Heihachi, Feng Wei
Street Fighter II Turbo - Guile, Fei Long, Ken
Kengo: Master of Bushido - That old, white-haired guy
Probably Virtua Fighter 4 once i get the hang of it, too. VF4 is cool because it is completely based on skill and move knowledge, button-mashing doesn't get you
shit. Sucks cuz that means none of my friends will wanna play it