I have a couple big ones.
World of Warcraft, of course, was the first. Playing it when it was new was an experience; with Australia’s internet and its initial teething problems, there was usually a 4-6 second lag between giving a command and having it acted upon. I’ve had a subscription to World of Warcraft almost continuously since it was released, although I pretty much stopped playing it after the Northrend expansion (the name of which I’ve forgotten). These days, I mostly keep it around so that I can open it up once every few months, check how a piece of their UI works, and then log out and forget about it again.
I was a huge fan of City of Heroes, and somewhat less so of City of Villains. I don’t know; the whole villainous thing didn’t really do much for me. And my PC of the time had trouble with the higher system requirements. Although in fairness, I really spent more time in the character editor than actually playing the game.
After City of Heroes died, I really enjoyed Champions Online. Like City of Heroes, I spent more time in the character editor than in the game itself, but I did get one character almost to max level. (This is a pattern for lots of games, for me; I seem to spend silly amounts of time in the character editors, and less in the actual game. I suspect that at least half of my ~300 hours in Skyrim were spent in the character editor).
What else… um… I spent a few months poking around in Second Life. Earned the equivalent of a couple hundred dollars selling some animated virtual scenery there. Turns out that when you have a lot of experience working on low-end console games, it’s really easy to create scripted stuff in Second Life which people are willing to pay you for, and are surprised use as few server resources as they did. Drifted away when I decided that there just wasn’t enough of a game there for my tastes.
Um… anything else? I played Runescape precisely once, and have been being spammed by Funcom ever since. DC Universe Online seems better than Champions Online in almost every possible way except for its character editor, so I stopped playing it almost immediately to go back to CO.
Ive made several attempts to get into GW2. Friends keep telling me how awesome it is, and I just can’t seem to make myself push past the introductory areas. I’ll connect once every couple months and have another several gift boxes. I’ll confess I don’t have the slightest idea what to do with them!