Paul Daley definitely. He went on from almost getting a title shot against GSP to becoming a bum really.
Paul's still UFC caliber, if they'll ever take him back that is. He almost beat Diaz for strikeforce title (best round Ive seen).
Personally, I always feel disappointed by Bisping, twice he gets within touching distance of a title shot then gets knocked out.
Its not easy being a Bisping fan