Treasure's over-the-top shooter, Gunstar Heroes, was THE game that first made me want to buy a Genesis. I haven't played the Wii Virtual Console version yet but now there's talk of an XBLA version thanks to a list of Achievements spotted on Xbox360Achievements.org.
We've seen Achievement leaks lead to actual announcements before, so this bears watching. Still, this is just a rumor for now so take it with a grain of salt.
Interestingly enough, the game's ESRB listing has it for Wii, Xbox 360, and PS3. Maybe there's a PSN version too? Hopefully. I wanna spread the Gunstar Heroes love around. Here's a gameplay vid of the Genesis original.