There's no MMO like your first.

[Daggerstrike]

First serious playing happened with Dark Age of Camelot.

[ValendianKnight]

First for me was Final Fantasy XI. After wanting to puke all over FF10's retarded disapointment, I was about ready to play a completely different kind of FF game, and this game delivered on that note. It felt MASSIVE compared to any other game of any genre I had played at the time. I would sometimes just run around aimlessly, and every trip outside San'doria felt like an adventure. It wasn't until I got into the grind of things that the game started to wear off on me. When it because about number crunching, camping, and watching all my friends cheat and buy gil because of a stupid economy. I played it for 3 years, and got a DRK to 75. After that, it was WoW for me. The game just felt decades ahead of FFXI for me, in almost every possible way. But for some reason, I remember FFXI the most.

[Fei]

Everquest would be the first, but Anarchy Online is the one I gush over. 

..like if you couldn't reach climax the first time because you were too nervous, but then totally nail the second one.

[MeshGearFox]

Furcadia.

[Lord Scottish]

My first MMO was Anarchy Online, but the first MMO that I really got into was Maple Story.

What's ironic is that I started playing MS about a month before the game that pulled me away from it (Mabinogi) went into open beta.

[Annubis]

No Ragnarok Online love in here?

[Wild Armor]

Ultima Online.

[Rapturous]

Nexus.

[Fei]

Nexus.

Oh my god... and people think free to play games suck these days!?

I've been desperately trying to remember the title for "Dark Ages", all I could remember was how unintuitive everything was.  Wow... wow.  Thank you.

Shattered Galaxy was pretty awesome though.  I expected Starcraft 2 to do what SG did with the territory wars, but whatever.  I can't believe these games are still alive...

[Rapturous]

Yeah, Nexus was more a social thing for me.  A buncha friends of mine played, so I got sucked in.  I had one buddy big on UO back then, but I went with the majority.  Nexus really soured my perception of MMORPGs.

[ShadowLaguna]

Maple Story. :)

[harmonic42]

FFXI was not only my first MMORPG, but it was what brought me out of the depression brought on by a crushing semester - girlfriend at the time, who was a super special soulmate kind of 3 years, broke up with me at the beginning of the semester, 2nd day of classes. Had to deal with being in multiple classes with her... same college major. Found out later she is engaged to marry a professor.  Of my college major.
 
FFXI somehow distracted me enough (too much) and helped :p

[Alisha]

my first MMO was asherons call. man back in the day peerless atlan staves were my babies.

[kyuusei]

My first was Phantasy Star Online. I dunno if it was really 'MM'ORPG, but regardless, it was also my last online RPG. :P

[D-Rider]

Final Fantasy XI was the first one I played for more than a month.  I believe I might have played that one five weeks. :P