Batman vs Wolverine
Okay, they have nothing but there fists, no prep or anything to study one another's fighting skills. Wolverine has somehow been relieved of his claws or simply can't use them, and has to fight with his fists.
This fight actually wouldn't be as one sided as some may think. Wolverine has some pretty decent fighting skills so he'd probably win about 2-3/10 but Batman would ultimately dominate.