There are three main categories I use to classify the movies I like:
(M) Mood-Changing Movies - Few are the movies that can shift your mood when you see them. Doesn’t really matter if it makes me feel happy, upset, angry, revenged, etc… once a movie can change my state of mine… I like it.
(E) Entertaining Movies - Go figure… usually high budget movies.
(A) Art Movies - Since filmmaking is an art, some movies can show a great video editing, sound editing, costumes, have philosophical touches, etc.

Before going over what I think are the best movies of 2009, I would first suggest “Michael Jackson’s This Is It“. As I said last year, the order is not random:

Watchmen (M&E&A) - This is the movie I like the most, not just because it’s a great one, but because I saw it when I needed the most.
Avatar (M&E&A) - If Star Wars revolutionized the film industry three decades ago and Matrix did it a decade ago, I think Avatar did it this time.
The Boat That Rocked (M&E) - Sex. Hot and passionate sex.
Invictus (M&A) - This is just another made for Oscar movie. I couldn’t help myself to notice that in South Africa they were having CRT flat screen TVs back in 1995. Probably it was just a technical issue to use old TVs, as they needed a refresh rate higher than 60hz to look good. The movie is about true leadership, uniting people and the 1995 Rugby World Cup that I had the chance to see on TV, not on a flat one, though.
The Hurt Locker (M&E) - Nicely made. If it would not be for the propagandistic idea in the end, the movie would be even better.
I love you man (M&E) - there were -5°C when we got out from this movie, but I was feeling it like +40°C ;-)
Star Trek (M&E) - Awesome job in reinventing Star Trek.
Fantastic Mr. Fox(A) - Art. Pure art.
Angels & Demons (E&A)
Everybody’s Fine (M) - Very well done. I have no idea why some people were laughing during the movie…
Paranormal Activity (M) - Brilliant! Probably the biggest ROI a movie can bring.
Nine (M&A)
Up (A)
The Blind Side (M) - when it’s about him/her, it doesn’t really matter what you think is better, but whether if he/she care about your opinion or not.
Sherlock Holmes (E&A)

Other good movies of 2009, this time in the order I watched them: The International (E), Underworld: Rise of the Lycans (E), Knowing (E), State of Play(E&A), The Proposal (E), Flash of Genius (A), The Soloist (A), Public Enemies(E&A), The Hangover (E), The Ugly Truth (E), (500) Days of Summer (M&A), District 9 (M&E&A), Inglourious Basterds (E), Julie & Julia (A), Mr. Nobody (A), Moon (M), The Informant (E), Coco avant Chanel (A), Couples Retreat (E), Law Abiding Citizen (M&E), The Men Who Stare At Goats (E), Disney’s A Christmas Carol (E&A), The Boondock Saints II: All Saints Day (M&E), 2012 (M&E), Ninja Assassin (E), The Road (M), All About Steve (M), Armored (E), Up In The Air (M), Precious (M), The Young Victoria (A), The Bad Lieutenant: Port of Call - New Orleans (E), The Last Station (A), The Lovely Bones (A).

What can I say, it was a great year to go to the theater. If my math is correct, 4 movies from the above I watched at home. In total I watched just above a hundred in the cinema room.

Again, shame on me, I’ve fallen asleep during two movies in the cinema room, Ice Age: Dawn of the Dinosaurs and The Imaginarium Of Doctor Parnassus. However, during one of them I was not the only one to do it, a friend of mine slept too, probably because of the night before :-)