Alot of the ones I'm going to mention are more from the fact that they came out before most of us were even born. I saw most of these on AMC, but I am really impressed.
SLEUTH (1972)Two of the best actors in history duke it out with wits and cunning in a sly and suspenseful game of cat and mouse. Seriously this is some of the best acting I've ever seen. Twist after twist they pull on eachother 'til the horrible nature of the game is revealed.
NIAGARA (1953)A
film noir in color. I like this movie for its awkward, creepy, quiet mood. And Marilyn Monroe doesn't hurt either
She's a lot better than most young actresses of today. Acutally the film's storyboard focuses heavily on the juxtaposiiton of Marilyn's sexy figure with the beautiful, eerie setting of the falls, and the dark premise implied. She's good at playing a little psychotic nympho and the male lead brings the best of that side out in her. It's actually a very dark movie.
SHAFT (1971)...Speaks for itself I think.... (This is the film that started Blaxploitation)