I don't know why, exactly, maybe I just played the game too late or something. Although Half-Life had some cool stuff as far as storyline and gameplay, there wasn't much that really grabbed me to become a big fan of it. That, and I never really found the ending to the game (I got to the part where you fight off monsters and teleport out to a different weird place floating in space somewhere, at which point I could do...absolutely nothing. Anyone know differently, or is this really all there is?).
I'm very excited to see the technology they're pouring into Doom 3, and see what they'll have done with the gameplay after all these years. Q3A is still by favorite deathmatching game by far, let's see if they can get back into the groove of a mission-based set.