Okay here's a Marvel/DC heavy hitter-fest.

This is a free-for-all on a desolate planet (so there's no collateral damage concerns for those involved with bleeding hearts), with a standard atmosphere.

Heroes:
Hulk
Thing
Colossus (current class 100 version, not the weaker teenage Colossus)
Hercules
Sasquatch

vs

Villains:
Solomon Grundy (not the intelligent version, the brute)
Rhino
Juggernaut
Abomination
Blob

I would have used more DC characters, but when you add Superman, Captain Marvel, etc. the issue of heat vision, magic, flight and such come in and this is just an old fashioned slobberknocker. This is a free-for-all, anything goes.