From Goodfellas:

After Sonny gave Tommy the $7,000 bar tab.
Tommy: "Ya wanna laugh? This prick asked me to christen his kid. I charged him $7,000."


Paulie: "Tomorrow we gotta eat sangwiches." (I love the way he mispronounces the word 'sandwich.')

From Godfather:
Vito mocking Johnny Fontaine: "Ooooh, what can I do?"

Clemenza to Michael: "Why dontcha tell that nice girl you love her? I love ya with alla my heart. If I don'ta see youa soon, I'ma gonna die."


From Donnie Brasco:

When Sonny took Lefty into the pitch black room before giving Lefty the lion as a gift

Lefty's reaction: "I think I shit my pants."
Sonny: "Whaddaya think? You was gonna get whacked?"