The 91st Academy Awards, also known as the Oscars, will be held on February 24.The Oscars ceremony celebrates achievements in filmmaking and has named the best picture winner every year since 1929. Some best picture winners have been forgotten over time, like "The Great Ziegfeld."Others won over films that critics say were more deserving, like how "Crash" won over "Brokeback Mountain."Not every best picture winner has remained as memorable as films like "The Sound of Music" and "The Godfather."Here are 10 movies that took home the best picture Oscar at the Academy Awards that have fallen through the cracks of film history. Critics thought "The Great Ziegfeld" ran too long at three hours.The dramatic musical "The Great Ziegfeld" won the award for best picture at the Academy Awards in 1937.The movie revolved around Florenz Ziegfeld Jr. (William Powell) and the spectacular shows he put on throughout his life. In addition to best picture, Luise Rainer won the award for best actress and choreographer Seymour Felix won for best dance direction. The early years of the Oscars celebrated many classics like "It Happened One Night" and "All Quiet on the Western Front" but "The Great Ziegfeld" has generally been overlooked in Academy Awards history. It is widely regarded as too long with a runtime of nearly three hours. In addition to the length, the musical numbers in the film have been largely forgotten and the plot seems to lag for modern audiences.Critics thought "Cavalcade" was a plodding depiction of British domestic life."Cavalcade" was a 1933 period drama that followed the lives of two families from 1899 to 1933: the working-class Bridge family and the upper-class Marryots. Touchstone events covered in the film ranged from the death of Queen Victoria and the Titanic disaster to the South African War and World War I. Of its four nominations, "Cavalcade" won three, including best picture, best director, and best art direction. Although the tagline on the poster promised it would be "the picture of the generation," the movie hasn't stood the test of time. Modern critics seem to agree that recent TV shows like "Upstairs Downstairs" and "Downton Abbey" have done a better job of capturing British life during this time period. In 2014, Radio Times critic Sue Heal wrote, "Critics at the time loved this rather sanctimonious jaunt through history. Seen from the vantage point of post-Second World War egalitarianism, however, it all appears quaint and riddled with accepted class differences.""How Green Was My Valley" was a drama that beat out "Citizen Kane."The 1942 best picture winner was "How Green Was My Valley," a drama set in a mining village in Wales that centered on the Morgan family. The picture starred Walter Pidgeon and Maureen O'Hara and was nominated for 10 Oscars. It ended up winning five awardsbest picture, best actor in a supporting role, best director, best cinematography, and best art direction. Despite its many awards, "How Green Was My Valley" is not as memorable as its best picture competitors, which included Orson Welles' "Citizen Kane," a movie that is generally considered to be one of the best films in cinematic history. It is largely liked by film critics, but "How Green Was My Valley" has its fair share of critical reviewers, including Jamie Gillies of Apollo Guide who described it as "a tedious working-class drama that did not deserve the accolades it received."See the rest of the story at Business Insider Click here to read full news..