my nomination: lineup scene in The Usual Suspects
http://youtube.com/watch?v=Hj5vERbLtYI (NSFW audio, obv)
each suspect in the lineup is supposed to say "hand me the keys you [censored] sucker", but Baldwin gets all into it and yells "give the [censored] keys you [censored] [censored] sucker mother [censored]!"