How's about this one: Who would be your favorite directors? Why? Which movies by them do you find especially good?
The director that I know for certain that I've seen all of his work is Terry Gilliam. I find his absurd worlds strangely evocative of the process of the mind, and more reflective of life than is truly comfortable. My favorite is probably Time Bandits, though I've enjoyed many of his works.
I've liked every Ron Howard film I've seen, but I haven't made an effort to go see them all. I can't explain why, exactly. Favorite, so far, IIRC, was Apollo 13.
Then, there's Kevin Smith. I haven't liked everything I've seen, but I've been intrigued by most in one way or another. I gave up on the porn-making film whose name escapes me long before it finished, and I've yet to see his latest film. Favorite was Dogma.
Then, there's Stanley Kubrick. Again, I haven't seen all of his work, but I've liked what I've seen so far, especially 2001, of course, and also Dr. Strangelove.
I've been dabbling with other directors to just go after their work, with attention to Hitchcock, and Welles.