John Cazale had the most incredible short career in the history of cinema. He only made five films, but those films were The Godfather, The Conversation, The Godfather Part II, Dog Day Afternoon, and The Deer Hunter, every single one a recognized classic.
Hepburn, Bogart, Grant, Davis, and Stanwyck do seem to have the most classic filmographies. I'd add Jimmy Stewart to that. You Can't Take it With You, Mr. Smith Goes to Washington, Destry Rides Again, The Shop Around The Corner, The Philadelphia Story, It's a Wonderful Life, Rope, Winchester 73, Harvey, Bend of the River, The Naked Spur, The Far Country, Rear Window, The Man Who Knew Too Much, The Spirit of St. Louis, Vertigo, Anatomy of a Murder, and The Man Who Shot Liberty Valance. Gregory Peck is another. Spellbound, The Yearling, Duel in the Sun, The Macomber Affair, Gentlemen's Agreement, Twelve O'Clock High, The Gunfighter, Roman Holiday, On The Beach, The Guns of Navarone, Cape Fear, To Kill a Mockingbird.
Among more recent actors, I think Phillip Seymour Hoffman and Julianne Moore have been in a lot of good to great films. Hoffman did The Big Lebowski, Happiness, Magnolia, The Talented Mr. Ripley, Almost Famous, Punch Drunk Love, The 25th Hour, Capote, The Savages, Before The Devil Knows You're Dead, Charlie Wilson's War, Synecdocte New York, Doubt, The Ides of March, Moneyball, The Master, and A Most Wanted Man.
Julianne Moore: The Fugitive, Short Cuts, Safe, Boogie Nights, The Big Lebowski, The End of the Affair, Magnolia, Far From Heaven, The Hours, Children of Men, I'm Not There, The Kids Are Alright, A Single Man, among others.
Joseph Gordon Levitt is putting together a nice career, IMO. Mysterious Skin, Brick, The Lookout, The Brothers Bloom, 500 Days of Summer, Inception, 50/50, The Dark Knight Rises, Looper, and Lincoln. I haven't seen The Walk, but I think his own film, Don Jon, is pretty decent, he's very good in Stop Loss, and there were good reviews for Hesher, which I haven't seen, either.
Then there's Leo. Gilbert Grape, Marvin's Room, Basketball Diaries, This Boy's Life, Titanic, Gangs of New York, Catch Me If You Can, The Aviator, The Departed, Blood Diamond, Revolutionary Road, Shutter Island, Django Unchained, The Wolf of Wall Street, The Revenant.