You guys heard of Death Battle?
https://www.youtube.com/watch?v=2UcO_0M0iUA
Here's some match ideas:
Kirby vs. Pac Man
Cody (Final Fight) vs. Axel Stone
Ryu vs. Liu Kang
Liu Kang, Marshall Law, Forrest Law, Fei Long, Ken Shiro, Kim Dragon (World Heroes), Jann Lee (Dead Or Alive), Ken Shiro, Rock Lee (Naruto), Kamen Rider Meteor, Might Guy (Naruto) battle royale
The Big Show vs. Andre The Giant
Muhammad Ali vs. Mike Tyson
Nightwing vs. The Winter Soldier
Hulk vs. Juggernaut
Billy & Jimmy Lee vs. Ryu & Ken
Billy Lee vs. Jimmy Lee (Double Dragon)