I'm a huge fan of the rocker chic look here (as you can kinda get a hint of in this Taylor Jacobson post I did a while back). And I feel like throwing a black leather jacket on just about any look can grunge it up, and I love that. Black jeans and a leather jacket? Yes. Sundress and a leather jacket? Yes. Pencil skirt and a leather jacket (if done really right)? Yes.
I have one that I've recently bought, so I'm good for about...two more seasons (yes, I make sure to get my money's worth out of my outerwear). Then it's off to picking and choosing which black is the right black, and what color metal I want the zipper to be.