Sorry but SNES is the obvious winner. And I like all three systems alot. But the SNES port was clearly the best. Best sound, graphics, and all around. For one it was the only system that "stock" had the controller for it. PC-Engine and Genesis are a joke without the 6 button controllers. I actually think that it would have been tolerable if the PC-Engine or Genesis version let you assign actions to the buttons as you wished, not forced you to use a shitty switch between punches and kicks. Think about it, wouldn't you rather just map Strong Punch and Strong Kick, and then another couple ones you might want to have based on your play style or character? That would be way better than the shitty switching system which atleast on PCE I don't recall ANY screen indicator of if you are set to Punches or Kicks.
Again I know this is a PC-Engine fan site, but it didn't get the best port. Now throw it on SuperGrafx with the Arcade CD-ROM and a good development team and definitely.