I've played a lot of MMO's, including WoW since release (I did stop just after TBC but returned about 3 months ago), but for me it isn't the ultimate MMO. Sure, it's got a hell of a lot of good things about it, but there are a lot of things that I miss that games like UO and SWG had. A dynamic and well-thought out skill system for starters. This level-based system sucks, but it seems to be the way all MMO's are measured now. The beauty of UO was that you could just change what you were whenever you felt like it. Bored of being a mage? Then pick up an axe, start chopping trees and become a lumberjack. You see someone with a lot of money, a nice house, a boat, and you want a piece of the action? Train some thief skills and pickpocket their key (using a cleverly devised method of course) and steal that house or boat from them. Want to tame dragons? Sure thing, learn Animal Taming and Lore, and off to Destard you go. Just be careful, they bite! How about becoming a Blacksmith, and selling your wares to everyone in the world? Well, that's easy. Buy a house deed, set up your shop, and off you go. Keep your vendors topped up and you're in the money
UO was truly fantastic, such an amazing game with so many avenues you could explore. PvP in that game was unrivalled. As has already been mentioned by someone else in this thread, it was the only game that actually made you CARE about the outcome of a fight, so much so that it was unbelievably hard controlling your excitement and the adrenaline pumping through your veins when you were fighting a PK, struggling to stay alive and save your "Emminently Accurate Broadsword of Vanquishing" and your "Valorite Plate Set" that was newly made by the shard's top Blacksmith. If you lost that fight, you would end up losing more than just the time of a corpse-run. It was truly a fantastic game, it made you feel real emotion and you had none of the stupidity and idiocy that WoW has brought along with it's millions of kids that seem to latch on to it.
Don't get me wrong, I really like WoW. I've got a level 70 Rogue, a 65 Priest, and I've started levelling a Druid for PvP, and I enjoy the game immensely. But if pre-publish 16 UO was still around, and was as popular as it used to be when I originally played it many years ago, I'd be there like a shot. While there are free shards available, they're usually customised to the hilt and are pretty crappy in comparison to what the real thing used to be. I played on a few some years ago and gave up after trying over 10 shards.
The same goes for SWG, although I was disappointed that there wasn't much penalty other than repair charges (initially) for death in PvP. But SWG used a similar skill-based system to UO, albeit slightly more restricted, but the crafting in SWG was second to none, and it was literally another life within a game. MMO's need to strive more at becoming this style of game, instead of just being the generic template that we have now. Skill-based with the ability to truly exist within the universe is how it should be.