Kindle for Android impresses on many levels (pictures)

The Home screen shows off books and other items in a 3D carousel-style interface.

The sliding menu bar on the left makes for an overall slick Kindle interface.

Built-in tools like a highlighter and dictionary make your reading experience simple and enjoyable.

Long-pressing a book brings up more options. One that I like is Shelfari Book Extras, which shows you community-curated factoids about your reading material.

With the Send to Kindle feature, you can view documents or images right from within the app. This feature can also be used to save articles from around the Web for reading later, a la Pocket or Instapaper.