Brick Joke: The seat David was about to get was him between two fat passengers before he sat with Buddy. The end of the movie reveals that the air marshal ended up taking that seat, adding to his bad day.
Butt Monkey: David. Everything that happens to him in this movie is because of the oversensitivity and Selective Enforcement of one flight crew. Then it turns out that the flight crew was faking the whole thing, as part of a gambit by Buddy to get David to face his anger issues. Except the air marshal; his hostility was real, because he was having a bad day.
For the Evulz: Subverted. In between we're given the impression of Buddy as a rather nutty Cloudcuckoolander (which he is by the way) who appears to be torturing Dave just for the fun of his twisted little games, though in end, it turns out that Buddy's Zany Scheme really was just to help Dave overcome his implosive anger problems to get him to stand up for himself.
Girl on Girl Is Hot: Subverted, as Dave is more creeped out by the gorgeous bisexuals who are his fellow therapy group members than aroused by them.
Have a Gay Old Time: Buddy forces Dave to pull his car over on the side of the highway and sing the song "I Feel Pretty." Dave's intonation of "I feel pretty and witty and gay" indicates that he recognizes this trope, and he's feeling both emasculated and humiliated.
I'm Not Angry: David's shtick for most of the film and he hides the anger pretty well, up until he finally snaps at his Jerkass boss and co-worker.
Jack Nicholson: The Guardian's review of the film described it as starring "Jack Nicholson playing a Jack Nicholson who's not as good a Jack Nicholson as the Jack Nicholson he played in About Schmidt or As Good As It Gets, but a better Jack Nicholson than the Jack Nicholson he played in Somethings Gotta Give.
Jerkass: Ironically, Sandler, who tends to play this character type, is here one of the few characters who does not fit that description.
Rant Inducing Slight: The crazy woman doesn't exactly take it well when Dave tells her not to take off her underwear.
Schoolyard Bully All Grown Up: As part of his "therapy," Buddy takes Dave to confront the bully who used to torment him in school. Dave is less than convinced, especially when it turns out that the bully is living in a Buddhist retreat and has renounced all violence. The bully is very apologetic about his behavior...except for when he pulled down Dave's pants in front of his childhood crush. In fact, he mocks Dave even further. They end up wrestling on the monastery grass.
Shell-Shocked Veteran: Chuck, despite the fact that the war he fought in, Grenada, literally lasted less than two months.