Definitely EVE. The concept is so damn amazing, but mostly it's ruined by a few things:
Unmitigated trolling/scamming/spamming. If I wanted that I could just surf the web without my virus/adblocker.
Utter domination by mega-corps. Yeah, you can putz around and waste your time doing low-level stuff. But anything significant is going to force you into conflict with one of the players/corps that have been around for years. Good luck.
EVE is definitely a game that's more fun to read about than to actually play. The sheer time investment required to do anything other than ride the coat-tails of a multi-year player is just not worth it.