This isn't a movie line but didn't want to start a thread, happened across this tonight. It makes me laugh that a missing art masterpiece was found in Stuart Little of all movies because 10 years after the movie came out some random Hungarian guy was watching it and spotted it.
The title of this thread read more like a thread of random lines from non pure comedies, even though that's most of the submissions so far, so I'll try to give one that I thought of after only reading the title and not seeing replies...