Always a hard question, I own the LS6b so would have to say it is my favorite to fly and often the one I fly the most. The T-craft and C-120 are fun, all 3 of these have the advantage that I have access to them and they are cheap to fly.
I like flying the Mooneys also, and the RV smile is hard to beat when going places, but turns out I do a lot more local flying than going places so the cheap, slow, fun planes tend to be my favorites.