Final Fight: Double Impact (PS3/PSN)Golden Axe (MD)Marvel vs. Capcom 2 (DC) Ready 2 Rumble Boxing Round 2 (DC)SNK vs. Capcom - The Match of the Millennium (NGPC)Soul Calibur (DC)Streets of Rage 2 (MD)Tekken 2 (PS1)
I don't know if it's my favorite, but I really like Combatribes. The SNES version is decent, but the uncensored arcade PCB is great. Smashing clowns' faces into the pavement never gets old.
I know the last few are arcade games but I did spend alot of time and money playing these in the arcades. They are all games worth finding on MAME if you don't have them already.