Ok, here's a game I just thought of. Not sure if anyone has done this before, but here it goes.
One person picks two contestants (ie Buffy vs Lara Croft). The next person chooses who they think would win in a fight. Then that person chooses another contestant to fight against the person they chose (ie Buffy vs Eowyn). Repeats are fine.

I'll start...

Buffy vs Lara Croft