Michael: Barzini will set me up through somebody close... that, supposedly, I won't suspect. Hagen: Somebody like me. Michael: You're Irish, they won't trust you. Hagen: I'm German-American. Michael: To them that's Irish.

Never get angry. Never make a threat. Reason with people.

Power wears out those who do not have it.

there was no greater natural advantage in life than having an enemy overestimate your faults, unless it was to have a friend underestimate your virtues.

I'll make him an offer he can't refuse.

ِAn offer you can't refuse.

Like many businessmen of genius he learned that free competition was wasteful, monopoly efficient. And so he simply set about achieving that efficient monopoly.