well as i said earlier i was thinking 6 words, 8 syllables. 'Don't be a menace in South Central when Drinking Your Juice in the Hood' is 14 words, 17 syllables so i guess my one aint that bad.
Your film's title is very important. It's the first impression people are going to get; if you are giving someone a spec script to read, and your title stinks, immediately they take their reading less seriously. If you are making a concept pitch, and someone loves your idea, and then you throw out an awful title, they feel like they've had the rug pulled out from under them. If you are already in the process of making your own film, you eventually want to get people to see it, and again, the title is the first thing they have to judge whether or not they want to see your film.
I would say it's all about getting it "just right", whatever that happens to be for your particular film. I think 6 words is probably borderline...if it works, it works. Five words probably has a better chance to work, but 6 just might fit your film exactly. If you go up to 7, your chances diminish even more, and by the time you get up to "Don't be a menace in South Central when Drinking Your Juice in the Hood", well people don't take you seriously anymore.
One or two word (one word and one particle) titles have impact. They're concise, they spell everything out right there for the potential movie-goer. If your film is called "Alien" or "The Terminator", people pretty much know what they are going to see. Or at least they have an expectation of what they are going to see, and this is not one time where you want to surprise the audience and catch them off guard. On the other hand, titles with 3-5 words offer intrigue...there may or may not be some clear insight to what the film is about, but there is some mystery there and intrigue that leads the movie-goer to say "hmm, that sounds interesting, I wonder what it's about?" Maybe they won't be hooked on the title, but they'll at least want to look up more information to see what your film is about, which is a pretty good start.
Sometimes that 3-5 range goes longer. Just thinking off the top of my head..."Eternal Sunshine of the Spotless Mind" comes to, well, mind. Anyways, there's a 6 word title for you that works pretty well I'd say. But the more words you add, the more and more likely it is you can come up with something better. I saw these examples on Terry Rossio's blog:
Cop Tips Waitress Two Million Dollars became...It Could Happen To You
--Terry Rossio argues in his blog that the Cop title is more descriptive and the latter title is less memorable, but if you're going to be pounding out more than three words for a title, I'd contend you don't want description, you want the opposite, something catchy with intrigue.
My Posse Don't Do Homework became...Dangerous Minds
--Enough said.
Sometimes making the title longer is better:
Coma Guy became...While You Were Sleeping
If you have something edgy or unique, something that fits JUST RIGHT, one or two words are usually perfect. For action, thriller, horror it seems like short, impactful titles are a good call. Other films usually fall into that 3-5 category.
But, like 2 out of 3....6 ain't bad. If it's JUST RIGHT.
Hope this helps.