BorrowLenses (I've rented from them a couple times, and spent a lot of time browsing), BigCommerce (I'm working on a site there) and Amazon camera stuff (I've spent a LOT there). Those are the most common ones, for me.
At work, sites I visit serve up Exact Target (they're a company) ads from Google. I spend a fair amount of time on the Exact Target website, due to work.
Apparently I want to by a small car (nissan Versa or Scion), have it delivered by Amazon Prime, and insure it with Allstate. I didn;t know I wanted any of that, but here we are. And with the money I save I want to take Air France to Istanbul for $997...actually, I really do want to do that.