Although intrigued with the game for many years (wrote a PvP program in 1997) the bug didn't grab me fully until August of 2003. I started playing, first against GnuGo (which I was told to be a bad idea), then on NNGS for a few days and then quickly on KGS, where I was much impressed with the interface and feature-rich environment.
At the moment of writing I've worked my way to a 18 kyu rank, no idea what my ceiling is going to be or when I'll reach it and I really should focus on my daytime job from time to time... :)
After a while I decided to switch to the DragonGoServer, where I stuck around for a year or two, only briefly returning to KGS.
After a relatively long break I have recently reclaimed my KGS username and am now around 8 kyu. On we go...