15 Insane Movies That Shouldn't Have Worked

3. Avatar (2009)

It's always foolish to bet against James Cameron, but even so, there was a huge current of skepticism surrounding 2009's Avatar in the lead-up to its release.

Without any A-list stars attached, no rooting in existing source material, a colossal budget and protagonists who resembled "blue cat people", the film seemed destined to under-perform at the box office.

Cameron, who developed a unique performance-capture system for the film, again proved his preternatural ability to produce entertaining, visually stunning films for a huge worldwide audience. Avatar's narrative may have been a little lacking, but as an experience, it unquestionably delivered.

The film scored almost $2.8 billion worldwide, making it the highest-grossing film of all time, a record it still holds almost a decade later.

Considering how infrequently Hollywood dares to gamble on new IP, and how rarely they're this successful, Cameron's confidence seemed crazy to the outside world, but clearly, he knew exactly what he was doing.