Amazon: Most items shipped between November 1 and December 31 may be returned until January 31, 2013. Electronics must be in new condition with all original packaging and accessories. After processing, gift returners will receive an Amazon gift card for the amount of the returned item once the return is processed.
Apple: Items from the Apple online store must be returned within 14 days of receipt (or 30 days for iPhones). You can return items (except iPhones) bought at the Apple online store to any Apple retail store for exchange or refund.
Best Buy: Thirty days for all items; receipt required. You may return items purchased online to a Best Buy retail store (photo ID required for in-store returns).
Target: Ninety days for most items; 30 days for electronics. (For items purchased between November 1 and December 25, the 30-day refund period starts on December 26.) The company permits you to make returns through the mail or in stores for most items.
Walmart: Within 15 days for computers and electronics; 90 days for most other items. Returns can be made via mail or at store locations. Without a receipt, you can make returns in-store only for store credit or exchange.