It seems like in this case we have a temporal error. A popular movie generated buzz now and skewed a result that people pronounce loosely as of all time.

Batman might be the best movie out recently but in 2 years time, it will be a dim and fading memory while the Godfather will retain its appeal as it has already proven that it can.

IMDB just needs a temporal filter to keep the latest trend from skewing the universal result.