The best ebooks site I’ve found, by far, is the archive at the University of Adelaide in Australia. The selection is outstanding, but the presentation is even better.
Steve Thomas, the curator, takes tremendous care to ensure Adelaide’s e-books display their best on any device. Most e-books, even commercial books, pay little to no attention to formatting, and the result all too often is books that are difficult to read.
A relatively dumb e-reader like a Nook or Kindle doesn’t give designers a lot to work with, but Thomas uses HTML5 to take what he can get from those devices.
The thing is, on a tablet, most commercial e-books display and read just about the same as they would on the lowest common denominator. That’s not the case with Thomas’ books, which will display with drop caps and stylized headings, if the device allows.
A lot of people associate “free” and “public domain” with “low quality.” In the case of Steve Thomas’ books, that’s not the case at all. Thomas’ freebies put every commercial e-book that I’ve paid good money for to shame.
If you’re interested in reading the classics for free, pay the University of Adelaide a visit. You’ll be glad you did.