Well I've played tons of MMOs(of which only WoW wasn't free) and I'm not saying that that qualifies me (especially since in most of them I only get to level 10) and I must say probably my favorite is DDO I even enjoyed it more than I enjoyed WoW but I kinda had a Hate relationship with WoW since the moment I found out I bought it (because it was inside of my Warcraft III battlechest instead of WarCraft III) so that might have something to do, and please don't tell me I could have gone back to the store to get WIII because I bought it somewhere in the middle of Arizona and back then I used to live in Guanajuato (in case you don't know it's somewhere in the middled of Mexico)... well I got sidetracked anyway the ones I've enjoyed are DDO, Dragonica Online and MapleStory (although I might be a little biased with that last one since it was my first MMO) I've heard that Runes of Magic is supposedly really good wouldn't know when I downloaded it there was an error in the server and I couldn't play it never tried again though, but by far the ONE online game I've had more fun with it's a free game called League of Legends (or LOL for short), man I love that game, it's not technically an MMO as it's more sort of an arena based multiplayer (up to 10, 5 per team) RTS in which you can only control one hero Unit there are over 30 different playable champions all I got to play with had very different gameplay styles, the only reason I don't play it anymore is because the PC I used to play it burned in a fire and this one that I have now doesn't run it (because it's really crappy it takes half an hour to open a folder and then it crashes).
Well and if you're to lazy to read all that basically I ended up saying play a game called LOL (League of legends) even though it's not an MMO it's free and it's Online.
PS: I really need to learn how to say what I want to say with less words.