Comix Zone for the Sega Genesis - Easily one of my favourite Genesis games. Basically you play as a comic book artist trapped in his own comic book. It's a beat-em up type game with a good dose of originality.
It also came out for the PC too.
<a href=http://download.com.com/3000-2099-10219160.html>Link to Shareware Version of CZ</a>