Even though I've yet to play it ill say AvP 99, I've listened to some of the tracks and they do nail the atmosphere well.
One thing I'll say about AvP 2010 though is that it did well with its tracks and the atmosphere of each character, despite some being repetitive and boring(the night club got a bit dull after awhile) and also the aliens side of the soundtrack particularly the 'alien 6' sounds quite haunting and tense c: