Apparently, you missed the fact that Dr. Eli Vance is played by 'Robert Guillaume'. He (literally)
is Dr. Eli Vance. Silly...
Also, the voice of Dr. Mossman is 'Michelle Forbes'. She was in '24', and also, looks somewhat similar to her character in Half-Life 2.
Besides, Rene Russo is ugly.
And 'Tom Cruise' as Gordon? Jesus...what's wrong with the world? Did we forget about a fellow named 'Gary Oldman' already?
I suppose you forgot about 'Dennis Hopper' as well. He would be the ultimate Dr. Breen.
In fact, while I was playing, I said to my friend, 'Doesn't he just remind you of Dennis Hopper? He's such a bastard...'
I had some pictures in my head for the rest of the cast, but I'm much too sleepy to completely pwn that list. You'll just have to settle for a half-pwn...