Blake Edward's S.O.B. I know I've seen it 10 times, and I still laugh my ass off, every time.
http://www.imdb.com/title/tt0083015/
Robert Preston at his best ...
Dr. Irving Finegarten: Hello Polly.
Polly Reed: Irving!
Dr. Irving Finegarten: You look like an anemic turtle.
Polly Reed: You're gonna let that SHYSTER on?
Dr. Irving Finegarten: I could sue you for calling me that, Polly! A shyster is a disreputable lawyer. I'M a QUACK!