The Best Movie Ever

There are dozens of movies made every year. Some are critically acclaimed and some are not. Some gross lots of money and some may not gross much. Some win many awards and some just don't. So, how can we determine which is the best movie of all time.
According to Yahoo Movies the highest grossing movie of all time is Titanic with about 600 million dollars of cumulative gross, followed Star Wars and Shrek 2 which accumulated 461 million and 436 million dollars respectively. Yea, these movies made a lot of money but personally I like Star Wars more than I liked Titanic and I also liked The Incredibles, another animated movie made by Pixar Animations Studios, more than Shrek 2. Money grossing can be a little deceiving since movies like Life is Beautiful are not exactly blockbuster but they are great movies.
The best movies are awarded every year around February and March in The Academy Awards Ceremony. The Academy Awards, or Oscars, are the most prestigious movie awards in the year. There are 24 different categories, but essentially a movie can only win 19 Oscars at the most since three categories award short films and the other three are Best Documentary, Best Adapted Screen Play and Best Original Screenplay, and a movie can only take one of these. The most Oscars collected by a single movie are 11. Titanic in 1997, The Lord of The Rings: The Return of the King in 2003 and Ben-Hur in 1959. Although all these are great movies people could argue that these movies swept the Ceremony because in all these years there were a lack of other good movies.
Good movies are identifiable but the single Best movie is not. My personal favorite is the whole Star Wars collection (can't wait for the third one to come out). What is yours?