Batman and Robin
Pork and Beans
Bill and Ted
Jack and Jill
Ornstein and Smough
Timon and Pumba
Bo and Duke
Romeo and Juliet
Goku and Krillin
For real, though, on my first playthrough I went with default names.
Each playthrough after that I had themes. So for one I was roleplaying 2 ninjas, so I named them Mitsu and Kona. One I was roleplaying JFK as a hypercharismatic telepathical knight, so I named my main dude Johnny. Currently, I'm roleplaying some germanic medieval mercenaries, so they're named Willem and Friedrick.