Hollywood may be a dream factory and deliver dozens of brilliant escapist thrill-rides every year, but it's also far more common that intriguing movies on paper fail to materialise into great cinema in execution.
There are so many variables which go into the creation of even a micro-budget movie, but when tens or even hundreds of millions of dollars are involved, there's only so much that directors and actors can do to affect the overall outcome.
It takes more than a neat log-line to make a great movie, as evidenced by these borderline-criminal squanderings of terrific concepts...
10. The Happytime Murders
The Pitch: It's The Muppets...but with an R-rating. A modern take on Who Framed Roger Rabbit's film noir satire, but aimed squarely at adults with brutal violence, wanton sexuality and rampant drug use.
The Reality: The Happytime Murders certainly didn't leave audiences wanting for R-rated material, but precious little of it was really funny or even basically entertaining.
The puppets look great and there are a few inspired moments, but with a lousy script which lacks the creativity, satirical verve or inspired vulgarity audiences were hoping for, this thing was rightly dead on arrival with critics and audiences.
It ended up being nominated for six Razzie awards, winning one for Worst Actress (Melissa McCarthy). But more than this, The Happytime Murders is a film so lacking in personality that it's already been totally forgotten.