Came up with a few more:
The Mummy (1959) Usually overshadowed by the 1932 and 1999 versions, this one's actually my favorite by a mile. Mummies aren't typically very scary, shambling about slowly like a drunk with a broken ankle, but Christopher Lee's mummy is actually a genuine threat. Imagine if The Terminator had been made in 1959. This mummy walks in a straight line to his victims and doesn't let anyone or anything get in his way, including heavy locked doors and point blank shotgun blasts. Unfortunately not on Blu-ray, at least in the US, but the DVD sells cheap. (Trailer)
La Jetée (1962) Probably best known these days as the inspiration for 12 Monkeys, but the two are quite different. This version is a half-hour short film made up almost entirely of still pictures with narration. Available on DVD and Blu-ray from the Criterion Collection, in a double feature with Sans Soleil, an unrelated film from the same director. (Scene)
Blacula (1972) It sounds like a joke, but the filmmakers actually took it seriously, and ended up delivering one of the better Dracula (or Dracula-related) films yet to be made. William Marshall, who also played the King of Cartoons on Pee-wee's Playhouse, is terrific as the lead. Available on DVD and Blu-ray, each a double feature with the sequel Scream Blacula Scream. (Trailer)
Kiss of the Spider Woman (1985) Two men, locked in a prison cell together, one a political fighter and the other a gay man arrested for "indecent" acts with another young man. You can probably predict that they don't like each other much at first but gradually become closer and more understanding, but William Hurt and Raul Julia are so interesting to watch (and the plot throws in enough twists) that you won't care. On DVD and Blu-ray. (Trailer)
Versus (2000) Trying to describe this insane movie is difficult. Imagine if Quentin Tarantino were Japanese and he remade Evil Dead 2 after watching The Matrix about sixteen times in a row. That's really the best I can do, other than point you to the trailer. On DVD and Blu-ray. (Trailer)
Hamlet (2000) and Macbeth (2006) These two never get the respect they deserve when it comes to Shakespeare film adaptations. Hamlet (with Ethan Hawke, Bill Murray, Sam Shepard, Kyle MacLachlan, Liev Schreiber, and Julia Stiles) is actually my favorite film version of the story (with all due respect to Laurence Olivier and Kenneth Branagh, whose versions usually get all the attention and admiration), and Macbeth (with Sam Worthington and Lachy Hulme) is, well... not my #1 favorite (Roman Polanski's 1971 Macbeth and Akira Kurosawa's 1957 Throne of Blood are far superior), but I still enjoyed it quite a bit and felt it was unjustly criticized and ignored. (Hamlet Scene) (Macbeth Trailer)
Turok: Son of Stone (2008) Most people these days seem to know Turok from the world of video games, but the dinosaur-fighting Native American goes back to a series of comic books started in the 1950s. This animated movie is based more on the latter than the former, and it does a great job with the material. At first glance it looks cartoonish, as if it's made for kids, but the stabbings, shootings, impalings, and dismemberment start in the opening scene and don't let up. Not on Blu-ray, but the DVD is easy to find and sells cheap. (Trailer)