Gotta be Half Life 2 - Ravenholm
At least you sorta know when and where it's coming from!
System Shock 2 had some great bits, especially when played with quadraphonic sound in a darkened room.
The Cargo level with all the boxed droids was great
It wasn't so much the action, as the atmosphere around it, similar to AVP.
Resident Evil 2,
Two way mirror in the interview room!