inb4 Eipok
Anyhow, try EVE Online, it is amazing. It has depth like no other MMORPG, it features a huge game world (about 5,000 star systems) with player-driven content an extremly advanced player-driven market and a incrinate political system driven by the alliances that occupy the lawless parts of space, the fact that all players are on the same server contributes alot to these systems.
EVE provides a proper risk vs reward system, where you WILL loose your stuff if you are not careful, and you are not babysat by a bunch of NPCs or game mechanics. Life in EVE is harsh, things such as scamming, piracy and threats (in-game, not RL threats) to obtain money from other players.
And the greatest thing about EVE is that you have the possibility to become practically anthing you want, if you want to become a pirate that lives off holding others ransom, or make your monthly dough by stealing what others have left behind, you can, if you want to make your living selling exotic dancers, you can.
Also, there are no classes, everything is skill-based and you can buy any skills you wish. If I start out as one race, I can obtain the skills for other races ships if I want to. If I've played for 3 years as a mercenary pilot, I can still choose take up mining or trading any day I want.
All in all, EVE is full of oppurtunity, making it very uniqe in the MMO scene.