I'd highly recommend 3D Bookshelf. It's only $0.99 but it includes tons of classic books and is updated with new ones pretty frequently. The quality of the app is also outstanding - you can flick the pages back and forth in 3d and it even gives you the sound of the pages flicking. http://itunes.apple.com/gb/app/3d-bookshelf-classic-literature/id352342690?mt=8
Right now, stanza is the best. I have iBooks and stanza on my iPad, and I still prefer stanza. It is a lot more customizable than iBooks.
can you purchase books? for instance my fave book is where the red fern grows, could i download that if i wanted to
No, that's the only downside. But they give you loads of free books and update them quite regularly. If you want books to download then get stanza.
