Poor War Machine. He spends most of his screen time trying to get the Avengers to laugh at one of his jokes. They aren't impressed.
Perhaps they appreciate his timely appearance more, though. He swoops down from Nick Fury's Helicarrier to help them finish off the fleeing Iron Legion bots. This is the kind of dependable superheroing that gets him tapped for the next version of the Avengers, as we see him report for training at the end of the film.
Maybe he'll find someone to yuck it up with on the new team.