I know you shouldn't judge a book by it's cover, but it really bugs me when movies, especially genuinely good movies, name themselves after one of their characters. Doing this doesn't tell me anything about the movie and it feels like such a waste of potential. If a movie has an interesting or thought-provoking title, I go into the movie already intrigued, but if it's just some guy's name the title might as well be "movie #200345". In a vaccum, which movie would you rather watch, a movie called Forrest Gump or a movie called Eternal Sunshine of the Spotless Mind? There are a lot of examples of really good movies that do this:
Thelma and Louise, Forrest Gump, John Wick, When Harry met Sally, Bill and Ted's excellent adventure, Good Will Hunting, Donnie Darko, Citizen Kane, Saving Private Ryan, Django Unchained, Logan Lucky, Captain Phillips, The Royal Tenenbaums, The Truman Show, The Big Lebowski, and My Cousin Vinny to name a few.
There are some exceptions to this. For example if a movie contains the name of a well known person that existed before the movie or if the movie's name refers to someone's title. Neither "Oppenheimer" or "the Godfather" fall into this pattern.