Everquest 2 - Don't listen to the haters, it's an incredible and deep MMORPG, with a ton of friendly (read: non-wow 12 year olds) people in it, and the pvp is awesome now.
Auto Assault - Kick *** massive destruction car combat MMO. Again, don't listen to the haters, try the game out (14 day trial, no credit card needed) and see if it's your thing.
I'd also recommend City of Heroes/Villians or even EVE Online.
Well me I think the best P2P games are RF online & WoW(I didn't play these game but I've saw many videos and they look great!!),RF becuase of the concep and the graphics and WoW because it look funny and so cool
Yeah Nergan is totally right. Plus if you want a more basic answer...as far as ratings and statistics show, WoW is currently the best online game.Period.