Skinny or straight jeans with solid-colored heels and a vest thrown on top. I think the vest does it for me. They can be added to nearly any outfit, but make you look pulled together and completely different when they are.
So as a short tribute to vests:
American Apparel: $36
And let's not forget cardigans!
American Apparel: $42. There're like 10 other colors too.
Also, although I'm not a fan of Paris, I have to say she looked quite dazzling at the Grammys last night. Look at that purple dress!