Nordstrom has such a liberal return policy that there is a legend of a man who returned tires to Nordstrom and received money for them! The story reflects the store's attention to customer satisfaction. Many consumers are perplexed when they turn their receipts and find no information on when the window of time is for returning items. That's because there is none.
There have been cases of people returning their purchases years after they bought them (and even used!). The best situation is having your receipt, but there are many cases where refunds and store credits were given based on the attached tags, current price of the item at Nordstrom, etc. If you don't abuse the policy, Nordstrom will most likely accept it.
REI allows you to return your purchase for a replacement or refund at any time. If you're an REI member, you don't even need a receipt. They have a record of your purchase!
Backcountry.com also boasts an Unlimited Return Policy. On their website, the company states: "We guarantee complete satisfaction and an unlimited lifetime warranty. If at any time -- now, next month, in 30 years -- you're not 100% satisfied, send your gear back for a full refund. No questions asked."
Costco is another company whose return policy is legendary. They guarantee the customer's satisfaction on almost all products with a full refund regardless of when you made the purchase. Costco now excludes specific products, such as electronics, due to people abusing the lenient return policy. Customers were purchasing TVs and returning them for a full refund years later and upgrading to another TV with the amount they received!
So these are all good companies to keep in mind if you are a) horrible at returning things within 30 days and/or b) like the security of knowing that you are covered if you buy a defective product.
What has been your experience returning products at these companies? Are there other places that should be added to this list of stores with the best return policies?