PSO (I was on a 26.8kbps modem, though, so I only got to "enjoy" it for one day, before giving up due to all the disconnections, and not being able to play it online). Given that the copy I was playing on Dreamcast belonged to a friend, I never bothered with PSO again, until recently, when I started half-heartedly playing the Gamecube version of PSO I+II Plus. It's a fun enough game... but I've been spoiled with PSU and Portable 1, 2 and Infinity.
Team Fortress 2 (on 360, through Orange Box) was my first ~true~ online multiplayer experience that I could enjoy. I racked up over a thousand hours on it. I even made a few long-lasting friends there, which led me into my next (and last) MMORPG console game...
...Phantasy Star Universe. I started on the demo (played it for over a year, with a few TF2 buddies, before finally going to the real servers). I invested some-where in the neighborhood of three-thousand hours, before I got tired of how Sega treated us paying customers. But it was still a fun game (enough so that I play AotI on my PS2, all three portable games, and occasionally pop onto Offline Mode for the 360).
Since I'm not sure, specifically, what constitutes a real "first game online" experience, I've covered all three experiences. I hope that's okay. --- http://www.youtube.com/user/PSUTerra
It makes me sad that we won't get PSO2, i'm very mad. One of my long time awaited games, nope not coming to the US. This is afters i poured 100's of hours into the DC,GC,XboX,PC versions of PSO yes each. Then poured another few 100 into PSU. --- SonicMetal? See the error in my name! I Skate DGK All Day. Brawl FC:4511-0201-6892