No doubt about my favourite line... when Michael has just rescued Ann from the oven:
Michael: Count to ten
Ann: 1, 2, 3, 4, 5, 6, 7, 8.. 10
Michael: (to Dolores, in absolute fury) You.. You cooked her nines!
After David Warner has explained that he can transplant the brain into a body, but she'll spend her life blowing rasberries and clapping, Steve Martin says "I know her, she'll hate that."
I love that, like you need to know someone intimately to know they'll hate spending their life like that.
"Damn your drunk tests are hard."
"Yes, yes, kill, kill."
"Are you out of your head?"