While Kindle scores over Sony in the low end model, and Sony offers some unmatched features over Kindle in the high end model, Barnes & Nobles Nook offers the most serious competition to Kindle.
The low end model of Nook costs $149, and offers just about the same features and functionalities of Kindle’s $139 model. The 3G model of Nook priced at $199 offers just about the same features that Kindle2 offers at $189. The major difference is Kindle’s qwerty keyboard and Nook’s touchscreen. While Nook’s touchscreen scores on appearance, its size, no more than that of a smartphone touchscreen, makes Kindle the better option.
The high end Nook Color costs $249 and offers serious competition for Kindle DX. Unlike Kindle, it provides a better color reading option that makes reading magazines a pleasure. It also delivers some web browsing and multimedia features.
The Nook comes with a chess and Sudoku program on it, but strangely does not offer the facility to read MS Word Documents, something that Kindle does.
Nook’s expandable memory up to 16GB is another advantage over Kindle.
While both Nook and Kindle come with long lasting batteries, Kindle’s battery requires shipment to Amazon for replacement, whereas any Barnes and Noble store replaces Nook's battery.
Barnes and Nobles allows lending digital content from Nook, permits free reading of any book from the Barnes and Nobles store for an hour, and supports PDF without conversion. The Nook however cannot read Amazon's DRM formatted books bought through the Kindle store.