For SURE it's the scene where Sollozzo is talking to Tom after The Don was (supposedly) killed:

Quote:
SOLLOZZO
It's good business, Tom.

TOM
I'll try, but even Sonny won't be able to call off Luca Brasi.

SOLLOZZO
Yeah... well, let me worry about Luca.


That ALWAYS gets me! 'Let me worry about Luca,' indeed ...

"You blamed him for Sonny -- you always did. Everybody did. But you never thought about me -- you never gave a damn about me."