What is a good MMORPG to play for a break from World of Warcraft?

Well, if you're looking for a no cost option, you can try any of the games from Perfect World Entertainment, like Perfect World International, Jade Dynasty, etc. They are all Chinese in origin and being brought over so there are some minor translation issues, but they're not bad. The clients are available as torrents and there is no fee to play; there is a marketplace where you can spend cash to get special items like crafting aids, mounts, bag expansions, etc.

if you're looking for something really different from WoW, you could try EVE, but if you're looking for a fantasy genre game, Conan isn't a bad choice.

Another suggestion - LOTRO. I started playing it since it went Free 2 Play its pretty good and has a lot of cool features. You can't access all the content, but with free to play you can get up into the low 30s of level and run several instances. All but two character classes are available. A lot of quests and other actions grant you Turbine points which can be used in the in game store to unlock things like bag expansions, adventure packs, etc - although except for some basic stuff, if you never put in any money, you'll probably have to save up and wait until the item you want is on sale (adventure packs which open regions tend to run around 600 points, which is like 5-6 dollars.

DCUO is fairly easy to new players.
Since the max level is 30 you can get to it within 2 or 3 days of intense gameplay
From there you have your sorta small set of abilities, so if you're starting MMORPGs this one won't be to confusing. You only have 15 points to distribute to your powers (active abilities) and the rest are innate abilities (well you got some kinda useless active abilities that require skill points, but you can only have 6 active abilities equipped and the ones from the powers are better than the skills, so you don't need them). You can get allot of skill points, but will never be to confusing since they are mostly used to get better stats.
It's fairly easy yet very fun and action oriented, I think it's awesome for a beginner.