My main one would have to be Rock Lee. His taijutsu is top knotch and so is his speed, along with the fact that he can use the gates like Guy. His character has not been developed very much, but people label his as fodder, which I don't believe anyone who can use the gates should be labeled as.
Sasuke is severly overated by fanboys and believe it or not underated by many people as well.
Kakashi fans say Kamui >>> everything which is kind of ridiculous but other than that I think he isn't over or underated too much, for his chakra reserves have at least tripled since the start of the series, which is a big help for him in many disscussions. (People can't point out his lack of stamina while trying to underrate him anymore.)