What online game is most like world of warcraft?

What comes to mind are a few games such as: Runescape: Runescape is a free MMORPG that is free to make an account and run around the free areas and worlds. The members only areas unlock more content, but is around USD $6 a month. However, you can play anywhere. The files are uploaded once you click your world to start playing. Guildwars: Not 100% sure about guildwars, but i have heard it makes a good comparison.