Little Miss Sunshine
I thought I was going to go out of my mind watching that crap in the first 15 minutes. They were so painfully dysfunctional. I was in disgust and mostly from experience of real family. But by the time the movie ended, for the first time in a long time, I was gasping for air, because it was so hilarious. I miss having side pain from laughing.
I think "Plane, Trains, and automobile" was the last time before "little miss sunshine" that I had excruciating laughter.