ebooks.com has DRM as a search filter so it is easier to find DRM-free ePUBs. Since you mentioned Sanderson, I believe Tor books (or is it Tom Doherty Associate

ebooks.com has DRM as a search filter so it is easier to find DRM-free ePUBs. Since you mentioned Sanderson, I believe Tor books (or is it Tom Doherty Associates?) actually publishes all of their books as DRM-free so there is a large selection of sci-fi and fantasy books to choose from. That being said, most mainstream stuff is just published with DRM enabled. Now for really older books that are public domain I like standard ebooks and project Gutenberg.