Personal experience:
Well unlike Kindle (beware the brain washing commercials here) 'Read me Binatone' can handle multiple formats of ebooks and even play background music, and play videos (H.264 and MPEG 4).
Ebook formats: txt, pdf, html, chm, rtf, fb2, epub, word, tcr, paml, doc, open e-book, open reader and mobi. They even provide you with this free link to convert some more formats before uploading it to your ebook reader.
http://calibre-ebook.com And http://calibre-ebook.com/user_manual/ (User manual)
There is a back light but you can reduce its contrasts and therefore saving your battery and your eyes from strain in 1 go! It also provide for cover, charger, headphones and usb cable.
And it is much cheaper than Sony, PRS-650 Touch edition, Apple iPad. Unlike Kindle which does not support epub ebooks, Binatone does. I paid for mine for €95.99. I highly recommend it.