The 2013 edition of the Amazon Kindle Paperwhite is faster, brighter, and more responsive. There's a $20 premium for the ad-free version, but with a price that starts at a low $119, ads or no ads it's a great deal.
Barnes & Noble recently released its next-generation e-reader, the Nook GlowLight. It's a nice improvement over its predecessor, with an improved lighting scheme and lightweight design. At $119, it's the same price as the Kindle Paperwhite.