WoW style game with multi-classing and housing. It even supports Lua scripting addons!
While there aren't as many base classes as WoW, you can combine any 2 classes so you end up with more combinations than WoW (Mage/Cleric, Warrior/Ranger, etc). When playing your primary class, you can only use some of the skills from your secondary class, but they definitely help. I've found its easier if you combine classes that use the same type of armor so that you don't have to maintain 2 full sets of armor.
One nice feature is that when targeting a mob, it will tell you if it is needed for a quest. There is also a NPC look-up feature on the map that helps you locate most NPCs that you need to talk to for quests.