Within the context of NBA players, some max guys and rookie contracts are the most underpaid due to artificial limits on their potential earnings. Most overpaid would be max guys who aren't really max guys but their team wants to keep them and wouldn't be able to replace them if they left so they go for it. These guys are often already the wrong side of thirty or thereabouts. These contracts look even worse after injuries. Then after that there are the guys who get long term deals above the midlevel who aren't worth it but the midlevel distorts the market, and so small market/bad/unattractive teams who wouldn't get them otherwise pay too much.
A couple of the less methodologically flawed (if now out of date) attempts to look at value relating to advanced metrics
Arenas is still getting paid so I guess he's worst value, unless someones really hurting their team.
Best value would be the best player, which to me is LeBron. Anderson and Blair are still on rookie contracts (though Blair's as a second rounder isn't on rookie scale but still limited in what could be offered) and due big raises this summer I think. But presently both fit the profile of "bargains" (if that's what you're looking for rather than LeBron, Durant, Dwight etc).
Just re-read your post and remembered you said Delonte not DeJuan. West is paid what he is because of personality issues, and is playing above himself so far this year.