Children of Men (2006): One of the best of all time. The whole thing felt to 'real'.

Mr. Nobody (2009): Great movie, excellent use of parallel universes to tell the story of one man's life/lives.

The Lord of the Rings: The Fellowship of the Ring (2001): Best of the trilogy, (serves as a placeholder for the entire trilogy)

Kill Bill: Vol. 1 (2003): Both films were a great (again serves as placeholder for both)

Das Leben der Anderen (The Lives of Others) (2006): Yes it did deserve to beat Pan's Labyrinth at the Oscars. Great movie.

Memento (2000): I don't know what I can say about this movie other than that it is awesome

Perfume: The Story of a Murderer (2006): great imagery, loved the film

Le fabuleux destin d'Amélie Poulain (Amélie) (2001): Heartwarming film with a wonderful soundtrack

(500) Days of Summer (2009): Best movie of 2009.

Kiss Kiss Bang Bang (2005): Robert Downey at his best, quick and sharp

I don't feel I can add anything from 2010 yet as I need at least a year to see what I think of a film compared to great films from a few years ago. Although I would have to day that the front-runners from this year would be Inception, Shutter Island, The Social Network, and Scott Pilgrim (although I haven't seen 127 Hours, True Grit, or many other promising films that will be released later this year)