I'll throw this out there too: Emeka Okafor.
I've always liked him, but I think he's another example of everyone immediately thinking he's overrated/overpaid because he's on terrible teams. If we take off the green goggles for a minute, just imagine the C's with Okafor instead of Perk. They lose almost nothing (if anything) defensively, get better rebounding, and significant offensive upgrade in the sense that Okafor, though no offensive master, isn't one of the league leaders in turnovers like Perk. If Okafor is on the C's the past three years, guess what? He's not considered overpaid at all.
Okafor
Min: FG% FT% Pts Rbs Assts Blks Stls PER
35.6 .447 .609 15.1 10.9 0.9 1.7 .8 16.39
33.6 .415 .656 13.2 10.0 1.2 1.9 .8 14.94
34.8 .532 .593 14.4 11.3 1.2 2.6 .9 20.15
33.1 .535 .570 13.8 10.7 0.9 1.7 .8 17.46
Then: 6 year, 72 million dollar contract (12 mil per, same as Noah)
Point being, it's amazing how quickly a guy goes from "Rising Bigman" to "Overrated deadweight contract."
A lot of it has much to do with circumstances outside of the player's control. For example, Okafor is but 1/5 of a starting lineup; it's not all his fault the other parts of the starting lineup have generally stunk. Second, the perception of Okafor is colored by the fact that he was in the same draft as Howard, and there was supposed to be debate about the better center prospect. So Okafor is being hurt perception wise for not being Dwight; had Okafor been picked tenth or so (like Noah), he'd be thought of differently.