An Android device would be able to use Ebookdroid, the best ebook reader (at least for pdf/djvu; its epub support is just okay) I've seen on any platform -- it just has so many features other programs are lacking -- like autocrop (gets rid of margins making the text part of book take up the full page), autosplit (automatically splits pages when people have scanned facing pages rather than each page separately), and autostraighten (when people have scanned some pages at an angle).
If you could configure how to render PDF links (mainly so tables of contents didn't look so aggresively yellow), Ebookdroid would be perfect for reading! (I added the "for reading", because I wish you could create and edit standard PDF annotations ---I believe instead of using native PDF annotations it uses a homegrown system that stores the annotations in a separate file.)
