I have only seen one other movie on your list Godfather 2. I agree that Pacino was fantastic. I probably wouldn’t have agreed with Gump but the last scene when he asks if his kid is smart kills me every time. It changes the entire movie for me and makes it great and one of the great acting performances for me.
I would add Christopher Walken from the Deer Hunter. Dustin Hoffman from Midnight Cowboy. Thought Heath Ledger was great as the Joker. Jack Nicholson in the Shining was pretty awesome.
These are mostly larger than life characters which allows an actor to shine. I think there are tons of excellent performances where the character the actor is playing isn’t as grandiose.
Many times I feel like if I am watching something and notice the acting then I am taken out of my fantasy. Take Bree Larsen in Room. Never for a moment did I not 100% buy her character. She was incredible in that movie IMO.
DeNiro in Taxi Driver and Raging Bull. I thought each was exceptional.
Peter Sellers, Gene Wilder, John Cleese. Long list of actors who fall more on the comedic side but are very good actors.
Billy Bob Thornton in Sling Blade was excellent too. Lol Samuel L Jackson great in Pulp Fiction.
My favorite is Clint Eastwood probably for Unforgiven. But Josie Wales is right up there.
Love Audrey Hepburn in just about anything.
Feel like I could add to the list and that I am focusing on older movies. I am sure there are some great performances today that could rival some that I have listed.