1. The Silver Age Green Lantern and the Golden Age Flash?
2. The JSA and the Frightful Four?
3. The Doom Patrol and the X-Men? (not that they were led by men in wheelchairs)
4. Sea Devils and the Fantastic Four?
5. Whitey Ford and Frank Sinatra? (Yeah, it's off-topic, but it's one of my favorite trivia bits.