These are rated by the following criteria: Budget (or cost to make the movie) and the current score from the rating aggregate site Rotten Tomatoes.
Some movies didn't get in because they didn't fit the criteria. For example, the Ed Wood film Plan 9 from Outer Space is arguably horrible, but only cost $60,000. Spider-Man 3 was expensive at $240,000,000, but got a 67% meaning it wasn't considered that bad.
What do you think? Does a bigger budget mean a movie is better? Are there any movies we're missing from the list?
UPDATE: Changed infographic. As numerous people have pointed out. The world GDP is in the trillions not the millions....I am, indeed, a retard. :P