Space Channel 5 vs Sonic Adventure! Ristar vs Chu Chu Rocket! Valkyria Chronicles vs Jet Grind Radio! Rhythm Thief vs Sonic 3! Power Stone vs Echo the Dolphin! Sonic and Sega AllStars Racing vs Shining Force! Skies of Arcadia vs Golden Axe! Crazy Taxi vs Dynamite Headdy!
I would be tempted to do a Sega Tournament even though I've only played 10 out of 16 of those games. However, I think there would be too much backlash since this is a Nintendo Board.