I'm ashamed to say I never played through the whole of half life, just the first quarter probably, this might make me play through it all.
Me neither. I did try a couple of times, but I must have got interrupted for some reason because I never made it too far. Last thing I can remember is being outside on the surface, getting shot at, and then jumping down into some kind of tunnel or ventilation shaft.
I actually started all three of the HL games (HL, Op For and Blue Shift), but never got far into any of them. Shame really, because I feel like it's too late for me to do it now. I just don't think I'd enjoy it enough.