Here is a great list of
spec-fic's love/hate relationships. I'm pleased to see same-sex as well as mixed pairings. It's not always about sex, although some of the same-sex pairings have been interpreted that way. I always figured that Doctor Who and the Master had a horrible breakup with each other, the way they acted. And Professor X and Magneto are even worse that way, though they aren't listed.
Anyhow, there's great inspiration for characterization and plot tension in these examples. I've had a lot of fun with Origami Mage and Kirigami mage along these lines. They may resent each other for most of their story arc, but when push comes to shove, they step to the same side of the line.