Love the Genesis Sonic games, those alone were worth owning a Genesis. However, Mario is better.
And X-Men 2: The Clone Wars is one of the best beat-em ups on any system. That was a big reason why I bought a Genesis back in the day (after already owning a SNES, though).
And of course all of Sega's arcade hits are undeniable.
So while I agree with you, Turf, about SNES being better, the Genesis is far from worthless.
I am gonna say, though, that the Genesis's sound SUCKED! I hate the farty noises that often come out of it, and the soundtracks of so many games just sound so similar.