Both games suck ass 1-20'ish.
FF is dominated 100% by economy. You absolutely cannot move, level, explore, or progress without money, and this will never, ever change. Leveling up your character in FF is akin to masturbating with a cheese grater, slightly amusing but mostly painful. Unless you select one of the "in" jobs you could find yourself looking for an exp party for weeks at a time with no success. FF endgame requires 20+ people as well, takes a woeful amount of time (by this I'm talking increments of months, if not years), is littered with popularity contests, hackers, mind numbing 24 hour spawns, and pyramid schemes. Unless SE makes bold moves, quickly, their game will continue to decay and die. Their content is capped by Dynamis Weapons, and their Interface is capped by PS2 limitations. Travel in FF is a fucking joke. Can take 15-20 real minutes to travel from town to town.
FF does have a great, great community. You'll make a lot of friends that you will most likely continue to talk to even after you quit. The main fun lies in rolling with your friends and having wild adventures.
The playerbase of WoW seems to be an average of 13 years old. The vast majority of it's people are so fucking stupid it will make your brain bleed trying to understand how their parents could fuck up so bad. The bulk of the WoW player base has an attention span of about 15 seconds. It is very easy to reach max level. This can be done in a little over a week if you go balls to the wall. Blizzard is not afraid to render their older content pointless. When the last expansion came out every last bit of equipment every last player possessed was immediately rendered obsolete, and the upcoming expansion promises to do the same. WoW's servers are down for 6 hours once a week, every week. There is no job-change option in WoW. If you start a new class (job) it's a fresh start with an entirely different character.
You can log onto WoW for 30 minutes and accomplish more than counting the number of times your moogle spins. Drops worth having are found in dungeons only you and your group can enter. You can enter these dungeons whenever you want, so there's no 12-36 hour window with 200 other people who hack-claim the monster and leave you wondering why you just wasted 18 hours of your life. Monsters who aggro will chase you for about 1 minute, then fuck off. No zoning and wasting your time. There is no exp loss penalty for dying. The focus in WoW is on content, not economy. Economy is a side-note at best. Jobs are constantly being examined and balanced to avoid having 3-5 jobs that are wanted and 12-13 that are mocked. Every class is relevant. For the monthly fee you can create up to 8 characters per server, rather than paying extra per character. WoW has real PvP that takes no extra time, money or friends to put together. See a battlemaster, join the queue, kill Gnomes.
Having played both to the 'endgame' level, I prefer WoW. It's approachable, not nearly as time consuming, and has PvP which is never the same two times. The developers of FF don't give a shit about their players, have done little to nothing to stop gil sellers, and honsetly have nothing as far as content left to offer unless they do something drastic. I miss FF's epic scope and community a lot, but it's just not enough to keep me at Fafnir for another 15 hours.
If you want a tough game that's involved, complex, and dying, FF is your choice.
If you want a game that you can play an hour and get something done, with a horrible community, than go with WoW.
