Hmmmmm, off of the top of my head: (........ Proper title is "The Boat that Rocked".... silly Americans.....)
My favorite movie of all time: American Graffiti. Most of the scenes went off-script, but they stayed in character enough to be kept in. "That can't be your car, that must be your mama's car!" Or From the same movie: (He was just meant to make the scooter stall, but they liked the accident so much they kept it in.) Best car chase in movie history: (If you watch closely the Charger loses five hubcaps.) More to come...