I've been playing RPGs since I was 12 or so. I bought the great D&D Red Box Basic set in '85 or so, and would play as frequently as possible, tho' it was rarely more than me and one or two friends. I played somewhat more frequently in high school, and in college RPGs and the internet became a wonderfully attractive alternative to actually attending classes. I met Karl in the computer room in the basement of Clement Hall at the University of Tennessee, as he was known as a guru in the ways of Nethack (about 5 or 6 of us would all log onto someone's CS101 account and play it on the UNIX mainframe). At one point he invited some of us to play in an AD&D campaign he was starting, and this became known as the Roman Campaign (if you e-mail and pester Karl enough, perhaps he'll be nice enough to put a summary of the campaign online). Eventually, both Kurt and I were able to rope our then-girlfriends into playing, and from there it wasn't hard to talk us into going to Gen Con, and the rest, as they say, is history.
In general, I spend about equal times playing and running, and I am the usual suspect in the group when it come to running Call of Cthulhu one-shots and campaigns. I buy far more RPGs than I could ever learn or run in my life, so as a result I own Vampire, Wraith, Werewolf, Ars Magica, Star Wars, and countless other systems I'll never run. I'm in the midst of running the group through TSR's "Night Below" campaign, but this has had to be put on hiatus as I'm working 50 hours/week at work, which leaves me little time to devote to running a campaign.