For movies, the big sellers seem to be comedies, usually with a romantic bent, and action movies. Thrillers and horror seem to get lower numbers, but are pretty stable in the market. Children's movies, usually animated, have been big sellers for a long time. And anything by a famous director usually does well.
I'm basing that entirely on what I've seen adverts for in the last couple of years, both adverts for new cinema releases, and for movies being shown on TV channels.
For TV itself, reality shows have good numbers, and sitcoms are all over the place.
As for books... UF is big right now, SF is stable, romance has always been a massive seller, erotica is making great strides, and the rest of the genres are doing well enough.
Basically I think the key thing to keep in mind is that if it's well-written and you send it to the right person (ie. keep trying until you find the right person) then you'll find success regardless of genre. There's a reasonable market for most things at the moment, as far as I can tell.
The only thing I know hasn't really gotten too far in the market is comedic urban fantasy. I know this, because I wrote a comedic UF novel, and trying to find a market for it is rather difficult, especially down here in Australia.
Anyway, good luck with your romantic comedy script.
I'll be writing a romantic comedy script in April for Script Frenzy (
www.scriptfrenzy.org ).
