RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.
Dealspotr - Dealspotr is like Wikipedia for deals.
DontPayFull - DontPayFull.com serves over 3.5 million visitors with coupons, offers and discounts each month.
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
Groupon - Each day Groupon offers a deal through local vendors in your city.