I still play Ultima Online on free servers. The game brings so much happy memories to me. But it wasn't my first MMO, my first ever MMO was The Realm Online
Eve Online, there's nothing like pinning down an expensive PVE ship in null with scrams and webs and listening to the other persons pleas and bargains...
I think WoW has to be my favourite, played on and off since Burning Crusade hit. Of late Wow has lost its appeal; I play pretty much exclusively for the PvP content and their incompetence when it comes to balancing has resulted in me cancelling my sub. Ive tried searching for a substitue but I cant help comparing every aspect of other MMO's to WoW and unfortunately most of the time I feel WoW does it better. Holding out for Mists of Pandaria!
I started playing in LK and I just started cata about 2 weeks ago, I havent been raiding but PVP gear is stupidly easy to get. From what everyone said, nothing can compare to vanilla. Oh well.
Me and my brother are about to give TOR a go since it's gone F2P and we've both wanted KOTORIII for ages
EVE. I have been playing for just over 4 years now (93.5 mill sp, so close to the big 100!!!) Haven't even touched capitals yet, just skilled up for all sub caps. I have been out of a corp for nearly 2 years due to real world commitments but will be looking to get back into it soon. Just to show off a little as I am proud of my character here is a link. http://eveboard.com/pilot/AlphaAngel I mainly mission but want to go out to null sec when I return. For me though the biggest hing holding me back for that is losing my +5 implants - it's all about the training time.
I'd say one of my favourite games that I still go back to is Dark Age of Camelot. Older game, but the PvP system / factions just make it so awesome. There are 3 factions instead of the standard 2, and all 3 have general classes such as a ranger / hunter, but each factions is slightly different in their skill-set, to make things a bit more diverse and interesting. End game is more PvP / Realm vs Realm focused and it is just awesome. The players are also very respectable. Normally if you're having a 1v1 with someone, if a 3rd person comes from the 3rd faction and they could kill both of you, they'll have enough respect to let the 1v1 continue. It's also very strategic and skill based, unlike WoW where you have an "OH SH*T" skill to get out of anything, there isn't that in DAoC, or you MAY have 1 but it has a long 15 minute cooldown. This encourages more co-ordination and also means that larger groups can still lose to smaller groups if the small group CC's the right people and pick the proper targets. Casters do crazy damage, but as soon as melee gets on them, they can no longer really cast, making them ineffective, there is no frost nova, no blink, no ice shield. I compare this to WoW as I have the most experience playing WoW and those were standard tactics. I also like how the realm vs realm allows for guilds to capture and claim towers, much like guild wars 2, but without the weekly resets. Each realm has their own main map, but you can venture into the other 2 realms easily and start to capture there items. Realms would want to hold and control more towers, keeps and relics, and the more you had, the better. GW2 nerfed their relics as certain realms were just over-powering all the others and controlling all 3 gave a substantial benefit. I also like how there are a variety of different specs that are all viable, depending on your play style. If you're say a warrior, you can spec into thrust, slash, etc. for different damage types and skills. I think the game just has the most depth, and items are useful, but they don't make or break your character generally. They also have realm ranks, which are like levels for pvp, the more pvp you participate in, the higher your realm rank, which gives you access to more specialized pvp based skills, allowing for more depth. Only issue I have now with the game is the dying player base, it's been around for so long and most of the people who are playing it are all veterans, even with free trials there are very few newer players. New players are turned off probably from older graphics, and the controls are a bit odd until you adjust. Still one of my all-time favourites as end game pvp is always fun, and each fight is something new and exciting. Small changes and tweaks in fights can make the difference between dying and winning.
I currently play The Secret World for the fun soloing and occasionally dungeon runs. And Vanguard: Saga of Heroes for the amazing (over 100) completely none instanced dungeons. Between those two I am very happy My favourite overall would probably be the original EQ but it's just so old now I prefer to play these newer ones. Rift I may return to at some point but I prefer these games for now. GW2 I didn't like at all.