Big fan of both franchises. Was super hyped for Diablo 3 but the Beta put me so off that I ultimately didn't buy the game. But I did buy NSMB2 and like it, so my vote goes for NSMB2 (shocking I know :P)
Ongoing bet with think-man: He wins if MH4 releases in any shape or form on PSV in 2013, I win if it doesn't.