I've played hundreds of mmorpgs just so you wouldn't have to =). Here are four massively multiplayer online role playing games worth your time and leveling skills:
4. World of Kung-Fu: http://www.worldofkungfu.com/ If you like martial arts this is a must try mmorpg, because there are 9 classes each specializing a different weapon. Quests are pretty straightforward but there are plenty to do, including fighting mini-bosses and bosses alike that are spread out around the world.
3. Perfect World: http://www.perfectworld.com/ Perfect World has some of the best graphics ever seen in a free-to-play mmo. Although the combat would be a little slow at times, the world of Perfect World is massive with plenty of different types of monsters to slay. Did I mention there are hundreds of quests to do? Not much grinding in PW, so hop in and give it a go.
2. Runes of Magic: http://www.runesofmagic.com/us/index.html Runes of Magic feels like a blend between Everquest and Guild Wars, with a more serious approach to graphics and gameplay. If you are looking for more "RPG" out of your mmo, this is the game.
1. Ether Saga Online: http://eso.perfectworld.com/ There is nothing bad I can say about Ether Saga Online. The anime graphics are spectacular for a free game, plus the gameplay is simple enough for anyone to pick up. There is no sign of grind, plus the quests are some of the best I've seen in an mmo of this type. This is a must play game if you love games like World of Warcraft or Flyff, because Ether Saga marries these two games into one great package. It is currently in closed beta, so it isn't without its bugs and glitches, but once those issues are ironed out this will be one of the best free-to-play mmo's out there.