When Stu is about to be killed by Elder in Stovington, he points behind him and exclaims something along the lines of "Holy crap, is that a rat!?" to get Elder to turn around so he can escape. It works.
When Larry becomes successful, a guy calls him and tries to talk him into making a remake of "Hang On, Sloopy". Larry eventually loses his patience, and tells him that given a choice between recording "Hang On, Sloopy" and being tied down and receiving a Coca-Cola enema, he would pick the latter.
Later, Ralph Brentner makes a similar joke: "If it came down to a choice between drinking Za-Rex and bullpiss, I'd have to sit down and think her over."
Observing the enthusiastic crowd at the first meeting of the Boulder Free Zone, Larry thinks that "This crowd would applaud Nixonís resignation speech and ask him to encore on the piano".
Most of the scenes with Nick Andros and Tom Cullen, particularly toward the beginning. They're the only two survivors for miles. One of them is deaf and mute, and the other one is developmentally disabled and illiterate. The fact that they manage to survive and work together can also double as a Crowning Moment of Heartwarming.
Stu, when being quarantined by the government, has all of his questions shot down on the grounds that they were classified. So he launches into a fake coughing fit to freak out the doctor. The doctor nearly has a heart attack and demands to know why he faked it. Stu grins and tells the doctor that it's classified.