A crossover fighting game consisting of non-DC and non-Marvel characters:
Dynamite
Vampirella
Pantha
Purgatori
Dracula
Hack/Slash
Eva
Dejah Thoris
Image
Spawn
Invincible
Savage Dragon
The Astounding Wolf-Man
Firebreather
Dark Horse
Hellboy
The Mask
Top Cow
The Darkness
Witchblade
Avatar Press
Shi
Coffin Comics
Lady Death
Valiant
X-O-Manowar
Livewire
Shadowman
Bloodshot
Ninjak
Just some examples (feel free to add any you'd also like to see if you're into this idea).