I tried to include why exactly I disliked each movie, but, just like with a movie you truly love, it's hard to put into words sometimes.
1. Oldboy. I found it weird yet uninteresting, especially everything after the hammer and octopus scenes. Felt like a clumsy post-Tarantino movie that traded emotional depth and a tight script for attempted shock value. That shock failed to resonate because I didn't know or care about any of the characters.
2. High Noon. The urgency isn't there, and without urgency, the film only has a shootout.
3. Die Hard 2. Wow was this terrible. I was shocked to see it got "two thumbs up" from Siskel & Ebert back in the day. Wouldn't be on the list otherwise
4. Le Cercle Rouge. Better than the previous three by a wide margin, but Melville's sense of pacing is excruciating, and the story wasn't interesting enough.
5. 2001: A Space Odyssey. Didn't like this when I viewed it years ago. Now that I've read a bit on the symbolism in the film I'd be curious to rewatch it, especially without expecting a traditional plot or characters. I don't expect the acid trip sequence to work any better, though.
6. American Beauty. Laborious, heavy retread of "suburban malaise".
7. All of the Star Wars films. Ok, so A New Hope and Empire Strikes Back are entertaining for long stretches. With that caveat, these are awful films. The dialogue and acting is terrible, the philosophy would be dangerous if it wasn't so laughable, and the world, typified by the cantina sequence, isn't as interesting as it thinks it is. From the beginning, it's pretty clear that the nuts and bolts of this world - politics, economics, religion - haven't been seriously considered and worked out.
8. The Three Burials of Melquiades Estrada. Love so many parts of this, but the bizarre depiction of Texas in the first half of the film ruined it for me. I didn't buy this Texas as factual or truthful.
9. Films Clint Eastwood has directed. I don't sense a distinct stamp on his films and I think most of them are pretty silly, especially his more recent work. Love his acting, though.
10. Rashomon. Only Kurosawa I disliked so far. I know others have found the sexual politics disturbing. I was fine with them, in context, but the film generally wasn't very interesting or provoking. If this is the best that film can handle ideas, then I'll stick to the written word.
HM: Magnolia was only ok; Raging Bull escapes the list only because I liked the editing/cinematography so much; The Postman Always Rings Twice had so much wrong with it that I don't know where to start; and Andrei Rublev had a lot of underexplained and uninteresting sequences (at least, for a non-Russian viewer).