Nick Gillespie says this is the 9/11 movie, and he may be right. Though I should note that this was also the year of Cloverfield.
8. The Class
Directed by Laurent Cantet
Written by Cantet, François Bégaudeau, and Robin Campillo, from a novel by Bégaudeau
It's a movie about a young teacher in the inner city, and yes I know that those are usually dumb savior fantasies, but this one avoids the clichés of the genre.
9. The Order of Myths
Directed by Margaret Brown
The mystic societies of Mobile, Alabama.
10. The Headless Woman
Written and directed by Lucrecia Martel
11. The Baader Meinhof Complex (Uli Edel)
12. Bronson (Nicolas Winding Refn)
13. The Wire 5 (David Simon)
14. Mock Up On Mu (Craig Baldwin)
15. In Bruges (Martin McDonagh)
16. Lies (Jonas Odell)
17. Civilization (Marco Brambilla)
18. A Matter of Loaf and Death (Nick Park)
19. Dr. Horrible's Sing-Along Blog (Joss Whedon)
20. The Facts in the Case of Mister Hollow (Rodrigo Gudiño, Vincent Marcone)
As you probably know, The Wire is a TV series, not a traditional feature film. So the fella in parentheses on that line is the showrunner, not the director.
Of the films of 2008 that I haven't seen, I'm most interested in Let the Right One In and Helsinki, Forever.