I am trying to find a good service to read ebooks (preferably for free) but as long as it is a good experience I don’t mind paying. Thanks for your opinion.
Depends on the platform.
If you’re on an Apple device at least, the built-in Books app works great for reading ePub files.
On Android I like Moon+ Reader, on my Kobo I installed koreader
Try moon reader pro for android, it got project Gutenberg and feedbooks built in and you can configure your own source also it has a lot of necessary feature like darkmode for books and stuff.
Libby is an online library, so you can borrow books from them. They also have audio books. All you need is a library card (which iirc you can sign up through libby).
You can read the books in the libby app itself (not bad, maybe a little clunky) or if you use something like a Kindle, you can have it sent to that, and read like normal. I believe it does others than kindle, but that’s what I use, so that’s all i know.
ReadEra.
The free app is so bloody good and adfree already, I bought it just to support the developer after using it for 8 years or so.
Tried several others before and nothing comes even close.
Android, no idea if any other version exists.