In the bathroom, Jenny 867-5309 is scribbled on the wall.
In the stall where you get the gloryhole trophy, you can see Mr.
When you look in the mirror in the bathroom, you can see the word "MURDER" reflected off the wall in the back.
On the desk in the Employees Only room where the security camera is, there is a never-ending spinning top.
When opening the door to Queen Bitch, Duke says "You make me wish I had three guns.".
Duke says "That's one dead space marine." This is the second helmet to find for the trophy.
Duke can find a dead soldier, and the soldier has the head of Issac Clark from Dead Space.
Before fighting the boss, Duke says "You're one ugly motherfucker.".
Duke says "I’m from Las Vegas, and I say: kill’em all!".
You can hear Duke say "Damnit Leroy!" This is a reference to the viral video of World of Warcraft, Leeroy Jenkins. Jenkins runs ahead of Duke and gets killed.
Duke is with Dylan and another soldier, Jenkins, up to a point, then they split up.
This is one of the helmets to find to get a trophy.
Duke is offered power armor, but he exlaims "Power armor is for pussies." Obviously reference to the Halo series.
There is a soldier cursing and complaining that he had to help is friend find his wife.
While in the casnio, you see the numbers 4, 8, 15, 16, 23, and 42.
When you're tiny and come across a mouse, Duke will say, "Now that's what I call a rodent of unusual size.".
While shrunk, Duke says as he jumps on the roulette table "Always bet on Duke.".
It's a common Easter egg in all of George Lucas' movies to his first movie ever.
Duke's password to his turret is 1138.
If you punch the guy, you can get a trophy. This is a reference to the Christian Bale freak out.
After you go backstage to escape, you see a man yelling at an assistant.
There are advertisements everywhere for Johnny O'Lenoman.
I don't have the game anymore, so I cannot check them. Feel free to post any you don't see on the list and I'll add them. I've decided to compile a list of all the Easter Eggs and references in the game.