Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
valpack - local coupon book online
BrickSeek - BrickSeek is a web application designed to help you buy those "Hard To Find" Lego Sets at...
Dealspotr - Dealspotr is like Wikipedia for deals.
Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.