The first product that's on sale is the Kindle Paperwhite. This device is the standard-bearer for all e-readers. Having owned a few Kindles over the years, I can safely say that the Paperwhite is an awesome device. It's a nice gift for that special someone, especially if they are voracious readers. It's only $100, which is a nice $20 savings over the normal retail price.
If you prefer movies and TV to books, then there's also a discount on Amazon's Fire tablet. This inexpensive device is a great way to bring your favorite apps and content with you anywhere, and it's on sale for $10 off its already low, low price, bringing it down to only $40. If you want to equip yourself and a loved one with a tablet, Amazon's also discounted the special 2-pack pricing to reflect this discount.
If you were looking for one of the other Kindle devices, there are two more that are getting temporary $20 price cuts. The basic non-backlit Kindle and the premium Kindle Voyage are both cheaper. I hesitate to recommend the entry-level Kindle, even if your budget is really tight. $60 is a tempting price, but take it from me, the lack of a light-up display is a dealbreaker. The Voyage is a nice device, but unless you want the page turn buttons on the sides of the display, it's functionally identical to the Paperwhite. The extra $80 isn't worth it for most people.