That last one was very, very tough, as I think Psycho is a superior film to either of these two (both of which I like), but both of these films are much better (IMO) than the 400 Blows.
Mulholland Dr. & 8 1/2 - Chinatown is a classic, but Memento is a film that I appreciate less after the initial viewing. The intersecting, opposed narrative was intriguing initially, but hasn't really held up for me.