Retail Me Not

Plenty of sites offer coupon codes, but RetailMeNot organizes them into one of the most intuitive directories we've found. Just enter a site (like Amazon.com) and RetailMeNot drums up a list of active codes. Since restrictions and expirations make some codes more reliable than others, the site even ranks them based on success rate, so you don't even end up wasting time with codes that haven't worked for other people.