One of my favorite little moments in the Trilogy is the scene when Michael arrives in Las Vegas and meets with Johnny Fontane in the room. Michael offers Johnny a new contract which he is clearly obligated to sign.

What's interesting is that you first see Johnny feeling umcomfortable and a little unwilling to sign the contract. But when he stares at it he suddenly smiles as he obviously sees the number on the cheque.

Great little moment as it's telling what kind of a person Johnny is because when it comes down to it, it's not about loyalty, it's all about business. You have to be a skillful director to pay attention to these kind of details.