So, I got an SNES the other day. W00T! This is a trade-off with my friend, whom I also bought one. Birthday presents for both o us. Right now, I have (this is actually his, but nonetheless):

Spider-Man/Venom: Separation Anxiety. Not a bad beat-em-up, only tought as Spider-Man. Venom is so much better.

Super Mario All-Stars/World one cart: Coming in the mail soon.

Mario Paint: Also coming soon.

Megaman X: Just old-school megamany goodness.

Super Star Wars original & TESB: Well, what can I say? TESB is impossible, and I just barely beat the first level of the original. These games are as hard as they say!