There's already a huge website devoted to this but it's mostly pop-culture and geekdom etc...
They have stuff like:
Cliff Claven vs Newman
Macgyver vs A-Team
Bruce Willis (Die Hard Version) vs Deathstar
Thundercats vs Masters of the Universe
Robocop vs The Bionic Man
and right now it's George W. vs King George III
www.grudge-match.com
thousands of people vote and send in responses as to who should be the winner of each match which are posted