It is crazy to me that Diablo 2 was not mentioned, yet. Second place: Modded Minecraft.
I let you be the judge of that.
I never owned a SNES but my best friend did. We played Wrestling, Mario Kart and Secret of Mana. He even owned the four player accessory and playing Secret of Mana with two other people was awesome - especially at the time.
Good old InternalFrameInternalFrameTitlePaneInternalFrameTitlePaneMaximizeButtonWindowNotFocusedState
It is crazy to me that Diablo 2 was not mentioned, yet. Second place: Modded Minecraft.