As others have pointed out the most overated players in general by far are the old school " pros" who appeared on episodes such as poker after dark etc. Most of these could only beat other donks & the vast majority of the whole lot of them are in fact now skint.Most players sitting in a 10k live MTT are now better than these old school players so FAME certainly does equal SKILL.There is the odd exception but there's not many very famous old school " pros" who can beat today's game. In my opinion the most overated/ underrated players today are ;
Overated - Phil Ivey / Tom Dwan
Underrated - Charlie carrell
All these "underrated" guys are players well within the levels of poker fame. How about a few that the media doesn't cover as much:
MUSTAFABeT, though painfully slow to act he has solid graph and won the 50k PPC and JLlammaa, who has quite the graph, and KKophgy. Also, iirc lottennice was victim of HS Trojan plant or something and he's still battling. That must do a number on one's psyche but looks like his form is pretty good in today's tough big bet environment.
this is a little outdated but i always had the most respect for guys like allen cunningham erik seidel and huck seed. not monsters on tournament scene but decent resumes all respected by peers when it comes to cash games.