Super Mario World. I don't really like Chrono Trigger, FF games, or Super Metroid, but those were all great games, too, and they all deserved mention here.
One thing that is throwing me is the SF2 inclusion. It wasn't even the best Street Fighter game for the SNES, nevermind best SNES game period. SSF2 crushes it in every aspect, from superior control, updated graphics, twice as many playable characters, better music and SFX, and better competitive balance between characters.
Balance wise, SSF2 is on a whole different level from most other fighting games. People have won major tournaments with bottom tier characters like T-Hawk. Ever see anybody win a major UMK3 tournament with Shang Tsung or Sheeva? It's pretty crazy how balanced SSF2 is considering when it came out.