Things that were not immediately obvious to me

1. Berkeley in the Sixties
2. The Big Sleep
3. Camille
4. Chungking Express
5. Ed Wood
6. Enigma
7. The Fall
8. High Noon
9. The Killing
10. The Last Days of Disco
11. Mad Max Beyond Thunderdome
12. Mulholland Dr.
13. Mulholland Falls
14. Othello
15. Richard III
16. Russian Ark
17. The Shining
18. Sunset Boulevard
19. The Third Man
20. The Treasure of the Sierra Madre

(Not only is this not exhaustive, it isn’t even a “top 20”. It’s just a list of 20 movies I’d suggest that you see. And yes, those are affiliate links.)

If you like Calcudoku puzzles (i.e. Sudoku plus math), you might enjoy Patrick Min’s site. It’s updated with new puzzles regularly, and includes some interesting variants, such as multicell division and subtraction, modulo operators, 10×10 and larger puzzles.

Incidentally, my solver can’t handle all those options – it only goes up to 9×9, for one thing – but if there’s demand, I’ll see about adding those features.