Your favorite science fiction horror film.
Aliens are taking over, but they are disguised as humans. The only way to detect who is an alien and who is human is to put on special sunglasses that allow you to see their true selves along with subliminal advertising that they have been using to control the human population. The rest of the movie concerns itself with bringing down the signal that masks the aliens' presence.
This is one of those movies that you will find yourself quoting endlessly afterwards. It's a fun escape, if you let your guard down and just go with it.
"I have come here to chew bubblegum and kick ass... and I'm all out of bubblegum."