Despite the rarefied air of the Academy of Motion Picture Arts and Sciences, its members nominate pretty popular movies for Best Picture. Since 1980, the highest-grossing film of the year has been nominated for Best Picture nine times — three times in the '80s and '90s, twice in the '00s, and once in our current decade. The highest-grossing film of the year has won an Oscar three times since 1980, most recently in 2003 with The Lord of the Rings: The Return of the King. The average winner earns 42.9% as much as the most popular movie of the year, which is to say that the average winner is a broadly popular movie. (If the average stands this year, the winner will be American Hustle or Gravity.)
The top-grossing nominee has been relatively unsuccessful only five times since 1980, and four of those times have happened since 2004, which is likely related to several record-breaking blockbusters (Shrek 2 in 2004, Revenge of the Sith in 2005, The Dark Knight in 2008, and The Avengers in 2012) and not to a more highfalutin set of tastes. The highest-grossing 2013 nominee, Gravity, has so far earned 63.6% as much as The Hunger Games: Catching Fire.
Even after removing the outlier years where the top film was also nominated for a Best Picture Award, the average gross for the highest-grossing Best Picture nominees is 54.6% of the highest-grossing film of the year. Pretty high earners.
The least successful winners, when compared to the highest-grossing film of that year, are Gandhi (1982), Crash (2005), The Hurt Locker (2009), and The Artist (2011).
Eleven out of 33 times, the winner is the movie that's done the most box office. The least popular movie has not won in the last 33 years.
There go your illusions!