Now that we've gone over which arch enemy could kick the others butt, which arch enemies are great matchups for eachother. Id have to say that Batman vs Joker and some PD's or Lackeys/Con Artists would be a great matchup.

sabertooth and wolverine are fairly even

I agree with CormacV Sabrertooth and the Wolverine are the best made match-ups.

Worst made?

Hulk - The Leader : while good in comic terms, squash goes the Leader

Thor - Enchantress : Eat hammer chick

Besides the obvious Wolvie and Sabretooth, Daredevil and Bullseye are a pretty good tandem

spider-man and the green goblin is a pretty good match, iron man and mandarin are also well matched up together. superman and doomsday would have been a more even match except for superman has a ranged attack.

Dr. Strange and Nightmare seem pretty equal, but I don't have Nightmare, so I'm not positive