Wow, choosing one scene is tough...
But if I'm forced to choose just one, I'll go with Ray, Rumsfield, and Art on their little stakeout with the night vision scope. Something about that scene is pure magic. Maybe it reminds me of when I would hang out with my best friend as a kid and sneak through people's yards, pretending the people in the houses were evil, scaring ourselves silly.
The nighttime atmosphere of the cul de sac, the creepiness of Hans with the trash can, the thunderstorm...I just love it!