Thanks for the link to ManyBooks. I had never found that one. Now to see what they have that I want to read.I've gotten a lot of e-books from Project Gutenberg. ManyBooks.net is another good source of free e-books in various formats. Amazon regularly has free e-books or ones on sale, so I check out their special offers for Kindle books on a pretty routine basis.
You can make notes, highlight, and bookmark pages on an e-reader. You can also skim pages, so there aren't really many advantages physical books have over e-books.
The biggest advantage physical books have is the wonderful smell and feel of old paper.
For those with a Nook reader, Barnes and Noble has a lot of low priced books. Of course, some of the e-books are more expensive than the paperback. Go figure. At least there is no shipping on the e-book.