I've played WAR, LOTRO, WoW, AoC, GW and Rift(bought it yesterday, played like mad).
WoW is the most popular one because it is so damn player friendly and polished. It has a lot of years on it's back as well - so I don't consider any MMO better than WoW. On the other hand; LOTRO has an amazing atmosphere that I feel WoW totally lacks. I haven't read Tolkien and I never cared for lore in any game, but when I play LOTRO I can't help to get sucked in and really enjoy the areas. The classes in WoW also has a purpose, which they used to have in WoW. They take debuffing and crowd control to a whole new level.
Rift is looking to become a contender as well... but that's because it has stolen EVERYTHING from WoW and WAR.
WoW is the most popular one because it is so damn player friendly and polished. It has a lot of years on it's back as well - so I don't consider any MMO better than WoW. On the other hand; LOTRO has an amazing atmosphere that I feel WoW totally lacks. I haven't read Tolkien and I never cared for lore in any game, but when I play LOTRO I can't help to get sucked in and really enjoy the areas. The classes in WoW also has a purpose, which they used to have in WoW. They take debuffing and crowd control to a whole new level.
Rift is looking to become a contender as well... but that's because it has stolen EVERYTHING from WoW and WAR.