I like Ridley Scott in a "how I would do it" contest.
He gets a certain mood in a picture that fits what I would go for if I had the talent ala Bladerunner, Alien, Thelma & Louise and Gladiator.
Best 20th century pop culture director Speilberg. But Speilberg has terrific range from Jurrasic Park to Saving Private Ryan to Shindlers List.
Terry Gilliam has some of the more provoking Kafka-esque style movies with his Monty Python work and the movies, Baron Munchausen, Brazil, 12 Monkeys and Fear and Loathing in Las Vegas.
Best American Urban style director. Sydney Lumet (Serpico, Dog Day Afternoon, Network, Twelve Angry Men, Long Days Journey into Night, The Verdict..etc..etc..)
Billy Wilder with Sunset Blvd, Stalag 17, The Seven Year itch, Sabrina, Some Like It Hot and Double Indemnity.
The Coen Bros with Blood Simple, Raising Arizona, Fargo, The Big Lebowski, Oh Brother Where Art Thou, Millers Crossing, The Hudsucker Proxy
Martin Scorsese, Hitchcock, Orson Welles, Akira Kurosawa, John Ford, Ingmar Bergman, Howard Hawks, Francis Ford Coppola, David Lean, Sam Pekinpah, Stanley Kubrick, Roman Polanski etc,,,etc,,,etc
I guess what I discovered making my comments is how many GOOD Directors there were/are and GREAT films we tend to forget about.