Super Sluggers, as some people said. This way, it could beat out Mario Kart Wii. MKWii wasn't bad, but it's multiplayer was the worst in the series. Why?
-You are limited to "Play this number of races in VS Mode before quitting. No Free Play option". Come on, having to select VS Mode again just to play more tracks does not cut it and is boring.
-Battle mode has the same restriction. Also, Balloon Battle being ruined with no survival option hurts it more.
-Online play is awesome, but NO CPU SUPPORT? That, the fact that only two players can go online on a single Wii and that both VS and Battle are restricted to "X number of races or battles at a time" in Friend matches ruin it as well.