Oh wow. I've never seen some of those before, but... just wow. That Pac-Man one is really out there. Maybe that's the origin of Pac-Man having arms and legs. Pro Wrestling is weird... does that guy have himself in a headlock?
Mario looks exceptionally buff on Donkey Kong, not at all like the pudgy plumber we've all come to know. He really let himself go later on.

The Street Fighter art is just bad all around. They really should have just reused the SNES or Genesis cover art.
Fatal Fury is not so bad, I think. Well, aside from the guys looking much older than the characters and fighting on a ferris wheel. It's trying to be a little too realistic, but it's actually has an impressive level of detail.