Doom for the pew pew gameplay. Duke nukem for the funny lines/cutscenes, the strippers/cheerleaders, freeze & shrinkgun. iow: Doom = gameplay Duke = comedy while duke nukem was fucking win and a classic... i still prefered doom. heretic was awesome too... good ol' heretic. (on the doom engine)
Pig Pen I also loved how you could set up duke nukem to play multiplayer on a LAN. none of these internetz bullcarp.
Heretic was always Excellent. Dark forces too, although I never got to play the full version Hexen 2 I liked quite a bit, 1 was not quite as fun but still quite good.
the movie is They Live its quite shitty by any standards but its a cool premise and its worth watching if you can enjoy shitty 80's quality movies