Warning: Incoming long-winded reply from MMO enthusiast
I actually still have an active account in guild wars, I just don't use it, for an idea of how little the game appealed to me. Yes it does have great graphics, great crafting, great dungeon running, and of course the "No Monthly Fee" thing (Although the 70$ Canadian was kinda pushing it for me) but the massive instancing really put me off. I did play with party's of people but I thought it was a shame I'd never run into other characters or party's unless they were invited first. There was no surprises but the monsters to be found. And the "Click and Watch" combat didn't really appeal to me either, even with the skillspammer classes. IMO it's more boring than EVE is said to be. Though I think it'd be more exciting if I wasn't such a carebear.
My favorite MMO's? EVE would be the best if you're looking for a long-term, endearing investment. I've been in a guild of about 6 people but we pack serious power and we've all been playing together for at least a year or two now, Corporations don't just come and go, albeit you're free to leave your PC as the experience gain is time based, which I love. Everytime I know I won't be back for awhile I just throw on a 3-month skill and tell them I'll be cruising a battleship by the time I come back. Albeit you must play more often if you expect to afford such things, it's a comfortable cruise through space for the casual gamer as well.
I played Maplestory exclusively for the Graphics. Though the userbase is immature to the point where it's just humorous. I have a folder full of screenshots of all the unsolicited trades people have offered me for my black bandana. Some of them even threw tantrums, opening trade again just to throw a insult-textwall and immediately close the window so I couldn't read it. Once I realized the target demographic is rabid 12 year olds I held a massive drop party, changed my password and never came back. I did betatest it though, the game was great til' the cash shop hit it. Which was surprising because I was waiting for it for months.
My friend told me I should look into Archworld for the 3D f2p MMO's, but I prefer Perfect World, though Archlord still looks promising. Perfect World has its share of problems and 90% of it's userbase either bitches about it on a daily basis or is constantly on the verge of quitting. The massive in-game map is 100% streamed together though it does have party-based instances that guilds tend to whore the experience out of. The customization is nearly on the CoH level and one class has the ability to fly from the start of the game. Otherwise, It's level cap is over 100 and it's mainly a korean grindfest. But it looks awesome, it's open PVP past level 30 (And many people praise the PVP Ad Nauseum, if nothing else) and it's totally free, though it's not free from the cash shop beast that plagues Maplestory. Interesting to note I betatested Perfect World as well.
D&D online was a blast with built-in voice chat and 'live action' fighting, (AKA click and swing) but the content level was sorely, sorely lacking and I found myself repeating the same instanced dungeon more than once and hit level 6/20 in about a week. The community there is definitely worth mention as well, as if you can squeeze into a full-headset party you'll likely find yourself playing for 8 hours straight before you even get up to shit.
Planetside is cool as well but again, Content issues. Once you've unlocked every weapon, vehicle and mech it's purely the metagaming that keeps you around. I once spent an hour sneaking painfully slowly into a heavily fortified base with my stealth suit and hacked the entire complex to our factions name in minutes without shooting a single bullet. They didn't have time to get over the confusion before we slaughtered them and took advantage of their vehicle spawn.
And thats my opinion on it all. Every MMO's got flaws, its choosing what you expect from the MMO that makes the decision
