Well, I don't think I could point to a specific movie anymore and say that's my all time favorite movie. I used to with Pulp Fiction, and it's probably the closest thing to my favorite movie...but...there's other movies where I have comparable favoritism towards.
Stuff like Children of Men, Chasing Amy, Garden State, Eternal Sunshine of the Spotless Mind, The Fall, Grave of the Fireflies, Fargo, Lost in Translation, Broken Flowers, Rushmore, Memento, Eyes Wide Shut...and basically every god damn movie Kubrick ever did...and Miyazaki.
And god only knows how much I love Scott Pilgrim. I also very much enjoyed Inception and The Social Network...I just haven't been able to rewatch them yet to see if I still do enjoy them. Even if I did see Inception a few times in theaters...