Way to many to mention but here are a few!

Pentangelli to Mihael-
Your father did business with Hyman Roth; Your father respected Hyman Roth ; But your father never trusted Hyman Roth"

Pentangeli to the senate commision
I----I----I never knew no godfather. I got my own family, senator"

Look the FBI guys promised me a deal. So i made up a lot of stuff about Michael Corleone'cause that's what they wanted---but it was all lies--uh---everything. And i kept saying---Michael Corleone did this and Michael Corleone did that---uh---so i said yea sure,why not.

Michael to Carlo
"Today i settled all Family business, so don't tell me you're innocent, Carlo."

Don Corleone to Tom
"Tattaglia's a pimp. He never coulda outfought Santino. But i didn't know until this day, that it was Barzini all along."

Sonny to Clemenza
"How's Paulie?"/Clemenza: "Oh, Paulie? You won't see him no more."

I could go on & on...LOL...