Who among you have played Doom?

I was introduced to the series through the 32X addition of the Sega Genesis port. It was the first first-person shooter I played before I knew what first-person shooters were, and before they became cool if I remember right. It was a lot of fun even though I was crap at it, though that can be said for nearly every game I played as a child. I never got around to playing the second or third game, but I thought I'd keep it open to talking about the whole series for the rest of you.

So talk about DOOOOOOOOOOOOOOOOOOOOOOOM!