Did I say this was going to be tough? Not with movie buffs like you.

(Shawshank Redemption was one of my 11 guesses)
Recap:
L = Library/librarian
1. The Music Man
2. Chances Are
3. The Philadelphia Story
4. Philadelphia
5. Regarding Henry
6. It's A Wonderful Life
7. The Shawshank Redemption
8. Fatal Attraction
9. The Big Sleep
10. The Librarian (2004), B-film, action adventure
11. Wilderness (1996), Amanda Ooms turns werewolf in a library
12. Harry Potter and the Sourcerer's Stone (2001), Hermione looks up sth in the library at Hogswart.
13. Birdman of Alcatraz (1962), prisoner loans many books from prison library.
14. The Ninth Gate (1999), rare book collector visits many private libraries.
15. The Return of the Unnamable (1993), heroes and police chase demon through university library.
16. The Name of the Rose (1986), mystery thriller in and around a medieval monastery library.
17. Hellbreeder (2004), heroine sees demon in city library.
18. The Time Machine (1960, 2000), hero visits age old library in the future.
19. Battlefield Earth (2000), hero is shown dilapidated library of Congress.