As well as I can remember, in brief. Apologies for the rampant acronyms, I'm sure at least one entry is bound to lose any reader. Maybe I'll fix that at a later date, using links and such.
EQ: my first MMO, and if they were all as fun as launch EQ I'd still be playing mostly offline RPGs. Not so much a "game" as "paying to be bored out of your skull," online, with freinds. Tried several times to get into it, never made it past a month.
DAoC: the first MMO I actually thought was fun. The graphics, the setting, and the (for the time) forgiving gameplay had me instantly hooked. ToA sort of killed things for me. Went back for a while around Catacombs when classic servers were added. Still one of my favorite MMOs.
PSO: I count this one because I was pretty active in the community when it first launched on the DC. Some of my fondest online memories. Played it on the DC, then played the hell out of it again on the GC years later. I hate grinding in an MMO, but the mag system and diablo style drops in PSO make grinding not just tolerable but addictive. PSU was a huge disappointment. I consider PSO BB to be the definitive version.
EQOA: played this game for a few months. Despite the fugly graphics, found it to be in most ways superior to the game that inspired it. Much more casual friendly, class designs were interesting takes on EQ1 classes , and at low levels a lot of engaging and rewarding quests. Unfortunately those largely run out by the early 20s, and it becomes "grind or die, the game" just like it's older brother. After getting multiple characters to the mid 20s and stalling out, realized the game wasn't for me.
AO: came to it late, a well polished game by then. Really fun for about a month. Once I got bored with randomly generated door missions, I found there wasn't a whole hell of a lot left to do that I thought was fun. Not a big fan of grinding to level (despite how many hundreds of hours I spent playing PSO).
CoH: the most fun MMO that I had ever played...for a month. Sensing a trend here. Still my favorite character creation system among MMOs by a wide margin. Not only the appearance editor (which is legendary), but also the "mix and match power sets" way of rolling a character. Combat, character creation, and PuGs are about the best you'll find in an MMO, to this day. Unfortunately the game itself is horrifically repetitive.
EQ II: nearly hated it at launch. Didn't enjoy the adventuring game. Too grindy, too few areas it was safe to solo in. Liked the crafting, but grinding out sub-components really began to wear on me eventually. Got up to teir III scibe and quit. At least I was fabulously wealthy by then. Tried it again right after RoK. Vastly improved in nearly every way, one of the most solid PvE MMOs out currently.
SWG: first tried it between the Combat Upgrade and the NGE. I was not impressed. I'm not one for pure sandboxes. To me dumping a player in the middle of a bunch of systems and expecting them to make their own fun is simply lazy game design. Offline sandbox games have had good storylines to follow for years. See Fallout, see Morrowind, see Grand Theft Auto. Until developers figure out how to do this in an MMO, "sandbox" MMO developers can bite me.
Word on the street is that SWG is a good blend of open and linear design these days, but I haven't ever gotten back to it.
WoW: just about lost my mind playing this game, like everyone. Oddly didn't take the first time I played it. Basically choosing blacksmith as the primary profession on my first character meant that by the early 30s the game had fallen flat on it's face. I was dirt poor, couldn't make anything that was useful (or at least better than cheap AH greens), and couldn't conceive of having enough money to buy a warg at 40. Tried it again a few months later, and it took in a big way. Met some folks I still hang out with today. Fantastic experience, even if I think the endgame utterly bites.
LoTRO: the best class based PvE MMO for a casual player by a very wide margin. Delightful cohesive world, an abundance of well presented stories to experience, steady addition of new content, and a solid crafting system. Hunter is the best class in an MMO, ever. Bought a lifetime sub after playing for six months. Still playing.
Tabula Rasa: an action based MMO that runs like ass on a mid level PC is not a good idea. Liked some aspects of it, plan to try it again after my next PC upgrade (if it's still around).
WAR: too early to say, but very positive first impression.