Speaking of great actors, I'd be curious to see what movie others would choose as the best movie for a particular actor. I'll start it off with a some, along with some comments for each:
Robert De Niro - Goodfellas (so many others, including The Deer Hunter and an "off beat" one, Awakenings)
Al Pacino - The Godfather or The Godfather Part II (tough decision there, although he was excellent (with De Niro) in Heat)
Joe Pesci - JFK or Goodfellas (another tough one, and of course Casino is a good one too)
Harrison Ford - The Fugitive or Witness (and another tough one! Still, excellent in Air Force One, and The 3 Star Wars Movies)
Kevin Bacon - Murder In The First (he has also been excellent in others, including JFK (not too big of a part), Flatliners, and Taking Chance (technically a TV movie))
Dustin Hoffman - Rain Man (most folks would choose The Graduate, and of course he was excellent in it. Some others include Midnight Cowboy, Tootsie, and Kramer vs. Kramer)
Gene Hackman - Hoosiers (so many for him, including The French Connection, Unforgiven, and Crimson Tide)
Tom Cruise - A Few Good Men (another one with too many to choose from! Of course there is Top Gun, and with the sequel Top Gun Maverick coming out in June, Rain Man, and The Last Samurai)
Jack Nicholson - The Departed, Chinatown, One Flew Over The Cuckoo's Nest, or A Few Good Men (man, so many good ones! As Good As It Gets, Terms of Endearment., etc.)
Clint Eastwood - Grand Torino (again so, so many! Unforgiven, Sudden Impact, Pale Rider, etc., etc.)
Brad Pitt - Moneyball (have not seen too many with him, although I do remember Oceans Eleven)
Tom Hanks - Forrest Gump (Philadelphia, Cast Away, The Green Mile, Sully, etc., etc.)
Meryl Streep - Kramer vs. Kramer (The Deer Hunter, The Post, Silkwood, etc.)
Shirley MacLaine - Terms of Endearment (The Apartment, Two Mules for Sister Sara, etc.)
That should be enough!