In this way, They Came Together is definitely an example of a postmodern piece. It is absurd and hilarious because we recognize all the cliches it makes fun of - cliches we are familiar with because of how many images - movies, TV, books and even songs - in which we've seen them before. This is the essence of postmodernism. How many of us have actually seen a man dash into an airport JUST IN TIME to convince his lost love not to board the plane? For one thing, he'd never get past security. But we instantly recognize that image, because it's been presented to us again and again in countless contexts.
They Came Together is a brilliant piece of satire with an all-star comedy cast, and I highly recommend it. (Warning, it is rated R, and there are a couple of - eek - sex scenes, so you probably shouldn't watch it with your grandma. Actually, definitely don't watch it with your grandma.)
Here's the trailer: