Slight self promotion, but Standard Ebooks has a few of the classics, and a few more of the classic fiction available as nicely formatted and accessible PD ebooks (epub, Kobo variant epub, and Kindle formats for each):
These are nearly always taken from the Gutenberg source transcriptions, but tidied up typographically and marked up using modern technologies. If you notice any problems with any of these we’ll happily take PRs!
At the risk of looking a gift horse in the mouth, the ePub versions I tried are rather unreadable, at least for me. Too many erroneously omitted spaces between words, odd hyphens breaking a word up in the middle of a paragraph, and mis-spellings.
If you have low quality source, eg OCRed scans, then you’ll never get a high quality ePub. It needs manual intervention and proofing to keep quality up. Not to say that archive.org isn’t useful - I’ve produced a collection of Keats poetry[1] as an ePub from their OCRed source in the past - but it’s not really consumable as is.
Yeah, I came here just to say that. I downloaded and unzipped the archive, then opened a few. The ones I looked at were badly formatted and had no TOC as well.
EDIT: added Project Gutenberg link.