Project Entropia is fun, I played it for a while a couple of years ago but it was faaar too hard to make any progress, it was (too) laggy and had few features. I know much has changed since then, so I might give it a try again, but don't expect earning loads of cash from playing PE

Btw, some people are really crazy and spend tons of money on the game, look at the news, that guy who bought that space-mansion, spending 100,000 USD on some bits and bytes? That's insane... On the other hand I heard he was some rich movie-guy.
Oh yeah one more thing, I actually worked on the Project Entropia both in Dreamhack Summer 2004 (
link for those who don't know what Dreamhack is), as you might have noticed it's a swedish game.

(Proud to be swede)
Oh, and to stay on topic, onrg.com is a pretty good collection of MMOs, just don't trust much on their reviews or ratings, some are reaaaly out of scope.