I've tested dozens of coffee makers as a shopping editor at Yahoo, and Keurigs are some of the most affordable and easy-to-use of the single-serve machines. Without a sale, the K-Slim retails for $130, but thanks to October Prime Day, it's half-off, down to $65. That marks the lowest price of the year.

According to the brand, you're guaranteed to have a noticeably whiter smile, and with this kit, you'll get some bonus express treatments for same-day results. This Prime Day sale drops the price to as low as we've seen it in years. Now that's something to say "cheese!" about.