This is a tough one. If the question were which team I disliked more, I'd say the Heat (I actually dislike them much more than I do the Lakers right now), although I don't know that I'd root for the Lakers over them in a finals (I might, though).
One of those things that I wouldn't know until the games started (but I have a strong suspicion about who I'd want to lose... I think.)
Edit: Okay, I'm not gonna split hairs here. Since I dislike the Heat more than the Lakers, I'd root for them to lose.