SNES by a mile.

Sonic was a good franchise but still couldnt hold a candle to Mario World 1 and 2.

Dare i mention Super Metroid, Zelda a Link to the Past or Super Mario Kart?

How about the Lufia games? FF 4 and 6. Secret of Mana. Shadowrun (which is an amazingly underrated game). Chrono Trigger. Illusion of Gaia. Fzero, etc.

Imo, the SNES was the GREATEST video game console ever created.