ok i'll start the ball rolling....

the Jesse hat....from Predator...worn by actor http://www.sportressofblogitude.com/wp-content/uploads/2009/07/predator02.jpg note the gattling gun is also a ref!



hangar 18http://www.imdb.com/title/tt0080836/

what else have you seen?

Hangar 18 is not a movie reference really.
Hangar 18 is the hangar that was meant to house the aliens / alien ship at Wright-Patterson Air Force Base. There have been many pop references to this including that movie and Megadeth's song "Hangar 18" (amongst many others I'm sure).

Reference: http://en.wikipedia.org/wiki/Hangar_18

It's not a movie reference, but if you have it on 360 and watch the different controller styles, there names are like, ''Duty Calls'' ''zombie infection'' ''floor of killing'' and they look similar to the game it referce

KILLING FLOOR for PC is the best zombie game

I don't remember which level it was, but all over the place there is graffiti that says "We Eat Cod"... coincidence? I know it's not a movie deal but whatever I thought it was funny.

the controller layouts are not movie refs they are to allow you to play in the style to which you are accustomed....i'm talking about stuff you find in the game...easter eggs :toughninja:

Yeah, I know but i thought funny that they added names reminding of the game

There's the toilet that's a reference to Demolition man (has three seashells above it).

There was a screenshot of it on the SD forums in their "Easter Eggs" thread.

Also not a movie reference but:
The heavy, automatic shotgun is called "Hjammerdeim". Say it out loud.
Stop! Hjammerdeim!