I haven't got a steady MMO at the moment, so I have been dipping into a ton of MMOs over the past few months:
Got a return-for-a-week-for-free mail from WoW, so I played that for a week. Had some fun doing the Isle of Time and SoO LFR, but when the week ended I did not have any urge to resub. I'm pretty sure i'll get 6.0 because it's just the most polished game in the market. But at the moment, nah.
Spend some time on LOTRO, got a char to max level but then there is fuck-all to do. I pre-ordered Helm's Deep on a whim, but after playing around in beta for a few hours i'm pretty sure I will only run a char through the story 1 time and then dump the game like a brick. The class revamps are horrible and the new Big Battle system is FUBAR.
Also went back to EQ1 since it went Free to Play, logged into my lvl 90 SK and found out I am naked since I can't wear any of my gear cause it has augs in it. Instant uninstall.
Played EQ2 for a few weeks, till I had 5 hotbars filled with crap skills. Uninstall.
Played Rift, got to lvl 30 or something. everything is so bland and uninspired. Uninstall.
Currently, I am having fun playing a little bit of Vanguard (playing a disciple) and playing some non-MMO games like Fallout New Vegas, Skyrim, Call of Duty, etc.
There just isn't a MMO on the market atm that is interesting enough for me to spend a lot of time on, so i'm happy with a tidbit of VG and some non-MMO gaming on the side.