The best A.I. in First-Person Shooters

[valvefan48]

Which first-person shooters do you think have the best A.I.?

Here's my top ten:

1. F.E.A.R.
2. S.T.A.L.K.E.R. Clear Sky
3. Crysis Warhread
4. Killzone 2
5. Left 4 Dead
6. Halo 3
7. Half-Life
8. SWAT 4
9. No One Lives Forever 2
10. Resistance 2