Granted sometimes these movies don't perform like producers had hoped in the case of movies like "Justice League" or "John Carter." On the other end of the spectrum you have smaller films no one expected to do big box office numbers, but defied the norm and turned into huge hits.
A perfect example is 2018's "A Quiet Place." The minimal horror film was shot on a budget of $17 million and has already made more than $270 million worldwide. It's currently the third highest-grossing movie of the year behind "Infinity War" and "Black Panther."
While "A Quiet Place" is the exception and not the rule, these sleeper hits happen now and again and it's always an impressive sight.
Here is a look at five of the biggest box office surprises ever.
The 2000 film "Crouching Tiger, Hidden Dragon" was a massive hit in the U.S. making more than $128 million against a $17 million budget. Not only did the film outperform what the filmmakers thought it would, but it did so with subtitles.
The movie is from China and had to be subtitled to American audiences, but they didn't stop us from making this movie one of the biggest hits of 2000.
M. Night Shyamalan became a household name with hits like "The Sixth Sense" and "Signs," but after a few flops like "The Last Airbender" and "After Earth" his name was used as more of a joke in Hollywood.
In 2015 he gave us "The Visit," which was both funny and scary and gave many of his fans hope for future projects. Then in 2017, Shyamalan released "Split" and it outperformed everyone's expectations from both a critical and financial perspective.
Audiences and critics both gave "Split" high marks and the film grossed more than $138 million in the U.S. alone. A sequel to "Split" titled "Glass" is set to hit theaters in 2019.
"Split" wasn't the only horror film to defy expectations in 2017, nor was it the most surprising. That crown goes to "Get Out."
Buzz about the small films spread quickly by word-of-mouth, and audiences flocked to the theater to find out what everyone was talking about.
The movie is smart, layered, funny, scary and flat-out good, which helped it become one of the biggest sleeper hits of all time. Not only did the film make more than $176 million domestically, it also earned a Best Picture Academy Award nomination and an Oscar to writer-director Jordan Peele for his screenplay.
This one is truly an anomaly.
"My Big Fat Greek Wedding" was a small movie, at best, and somehow it became the fifth highest-grossing movie of 2002. You might say fifth isn't that notable, but consider the movies that finished ahead of it: "Harry Potter and the Chamber of Secrets," "Star Wars: Episode II – Attack of the Clones," "The Lord of the Rings: The Two Towers" and "Spider-Man."
Here are some of the movies it beat out: "Signs," "Austin Powers in Goldmember," "Men in Black II" and "The Bourne Identity," among others.
No one thought "My Big Fat Greek Wedding" would get anywhere near the numbers it accomplished, but it turned into a box-office juggernaut, and I have to assume that Windex sales went up as well.
Of course, this was going to be on the list. The odd and quirky comedy that started out as a student film ended up being a box office smash and a cultural phenomenon.
Whether you get "Napoleon Dynamite" and its humor or not, a lot of people did and they paid to watch it over and over again.
While a $46 million gross doesn't seem impressive to the hundreds of millions as some of the other films on this list it's important to remember that no stars were in "Napoleon Dynamite," it had a no-name director and it cost just $400,000, which is madness considering anything under $10 million is considered low budget.
"Napoleon Dynamite" is the type of film you only see once in a very long while in terms of the content itself and the way it performed at the box office.