Double Dragon for MS was a pile. Sure it had arcade like layout and 2 player simultaneous play, but that didn't make it a good game. The enemies often scored cheap hits. Collision detection wasnt that great.
Otherwise, I don't find MasterSystem so remarkable, aside from the Sonic game ports it got. It did have PS1, which I never played, and also a port of Rastan. I think Rastan could of possibly saved the system for me if I knew about it as a kid.