Good feral MMORPG games?

Guild Wars Trilogy is an amazing game. I enjoy being able to play the majority of the game on my own, but there are times when you need to ask other "real people" to join your party. At first I was a little shy to do so, though I soon realized there are quite a few players that can teach you new tricks in getting around or ways of doing battle. Now I am hooked on the whole thing and look forward to playing whenever I can. I'm still on the first game (Prophecies) and know that I will enjoy playing Factions and Nightfall just as much.