A Half life movie should not be made. Why, that was the point of half life, that is why it became so popular. You actually felt like you were him, I liked the train ride showed you your backround, and black mesa's atmosphere. It is supposed to make you feel like you were him.
Remember the begining of hl2? After you get passed the stuttering Gman(hated that part) it was like hl, gave you that feel that you were him, The part where the cops break the doors, then you have the roof chase.... best part in any game, then you meet Alyx, went to the lab, then crap happened, then you take your first step....
.....boom, feelings gone. that is were it became boring.
Doom 3, were i am so far, is like that makes you feel like your in it. And do you mean the liandri conflict? I hate that game, don't buy it. Seriosly, it is an insult to shooters and fighters at the same time. the only good thing about that is when you turn on melee only, quad jumps, wall running, and speed. it can get fun there sometimes.
and half life 2 is a great game better than half life i would say, if it wasn't a sequel, it would have been much better as it's own game(wouldn't be that hard eirther)