When it comes to movie titles, it's best to go as simple as possible. To do otherwise would create unnecessary confusion, so just name an object in the movie and keep the syllable count low (People don't like a lot of syllables jumbling around in their head like pinballs). For example: If the movie is about some babies, call it Babies; If the movie takes place in some oceans, call it Oceans; if the movie is about some hilarious married killers, call it Killers; etc. No articles. No mysteries. Just name a noun, possibly pluralize it, and, boom, there's your movie. (Incidentally, if The Hurt Locker had been called Boom, it could have been much more successful.)
50 Cent has learned this lesson well. After Get Rich Or Die Tryin, he's learned how to pare his movie titles down to the bare minimum:
(via Vulture)
Gun. Behold the simplicity! Now the audience knows exactly what this movie is about: Gun—and possibly Val Kilmer morphing into a gun, which would sort of explain the whole "One gun. Many lives lost" thing, and also why Val Kilmer is nowhere to be found on the poster, but mostly gun.