My first character was a paladin. I'd been told to play one by the people who talked me into playing WoW in the first place, and I kind of liked it. As much as anything, it was a sentimental attachment. My friend Chris had made the character for me, and named it, and my friend Mark had taught me roughly how to play it. I was still kind of a noob, when I was leveling my way through a zone and saw what I now know was a shaman. I'd been trying to kill some mobs, and having a hard time, partly because I was new to the game, and partly because I was specced into holy.
This shaman planted their totems and unleashed a torrent of lightning bolts into one of these tricky mobs, and it died before it even got to them. I was impressed! I didn't even know, at the time, what that class was, but a brief description to my guild-mates soon clarified it. I decided at that point that my next class would be one of those, and rolled one the same day. And somewhere along the way I lost the bug for massive DPS and started healing.
That's me, but what about you? What made you choose your class? Was it seeing another? A feeling of personal identity? A preference from previous games?