The scene where Woltz is chewing out Hagen about letting Johnny be in the picture. Robert Duval's acting in that entire sequence is brilliant! Just had to get that one off my chest.

Duvall's acting in nearly EVERY scene he's in is 'brilliant'.

He is second only to Brando in terms of facial expressions and little nuances that define and add depth to the character he's playing.

Apple

I agree. And honorable mention as far as facial expressions goes to the scene where he hears Sonny and Lucy behind the door. That little smirk on Duvall's face is just priceless.

Yes, I was thinking of just that moment, among others!!

Really, you could name almost EVERY scene and there's some gesture and/or expression that solidifies the character.

In fact, I've always felt that Duvall is even better in GF than in GFII.

Which reminds me...for which one did he get the Oscar nomination....?? I always forget.

In that scene he remains perfectly calm in the face of Woltz's tirade. That reflects his complete confidence in Vito's ability to get what he wants for Johnny and his advice to Tom to never get angry and never let anyone know what you're thinking. Perfectly played. Of course the, "Mr. Corleone insists on hearing bad news immediately" is classic.

Best Actor in a Supporting Role - The Godfather

Thank you, Mig...amazing year that was. Joel Grey beat out all 3 Godfather nominees (and I forget who else) and got the Supporting Actor Oscar for his rose as the Emcee in 'Cabaret'.

I do remember Grey himself appearing on The Mike Douglas Show a few weeks later and admitting being totally surprised as he was certain Al Pacino would win.

Interestingly, Joe Pesci would say the same thing almost 20 years later!!

Apple

Brando and Duvall play great parts and do a lot of acting with facial expressions and eyes but so does Pacino especially in the cafe/making his bones scene,he looks so woried and scared after retreving the gun his eyes are darting all over the place then in a split second his eyes change to these emotionless eyes and he gets up and pulls the trigger,it was the scene that saved the movie as we know it.

Brando's exhale at the moment Tom tells him that Sonny is dead is one of the best moments in the movie.

That is superb acting. It is the film version of the novel played sans pareil: "For just the fraction of a second the wall of his will disintegrated and the draining of his physical strength was plain on his face."

Duvall is fantastic actor. I love the way he act the Don's conssigliere. I have his autograph

Maybe the best small gesture in GF1 is when Signor Vitelli pulls up his suspenders before performing the formal act of inviting Michael to meet his daughter.

That entire scene was one of the best in the film. It also represented another major step in Michael's re-connection with his family, his heritage and (Vito's word in the novel) his destiny.
Still another fine example of gestures and expressions: the way that Cicci and his men surround Tessio at the moment he realizes that the jig is up. And Cicci's "exuse me, Sal" as he frisks him, is another memorable touch.