I really like PJ's answer and ideas that are inspired by food (beer is food!). A guy named Peter that I (and probably a few others here) know on Twitter as @SimplyBeer created a brew based on his love of Reese's Peanut Butter Cups: Peanut Butter Porter. I haven't tried it yet but everyone who tried it seemed to love it. Really want to try brewing this soon. Here is his recipe: http://www.simplybeer.com/blog/2010/03/19/homebrew-peanut-butter-porter-recipe/
But most of my own recipes are inspired by beers that I've tried and loved.
Smuttynose does a really hoppy Imperial Stout, and I decided to try to brew one myself using a lot of Chinook hops (they use Cascade, but I thought Chinook might work better). I wouldn't say it was as good or better than Smutty, but it came out awesome and I'd definitely do it again.
I also just got to try some Stone Sublimely Self-Righteous that has me wanting to do a black IPA/Cascadian Dark Ale/whatever you want to call the style (I'm not a fan of the term "Cascadian Dark Ale", I'd call it an India Black Ale if it were up to me).