I think that Njalla was started by well known Pirate Bay website for torrents, and it's probably the best option for privacy like bitmover said.
It's important to know that this doesn't mean that you can register any illegal website and domain with Njalla, because they took down multiple domains last year, and maybe they even provided crypto transactions to authorities.

One alternative is Flokinet.is, that can be used for hosting and domain registration only with valid e-mail address, and they accept payments with Bitcoin, Monero and other cryptocurrencies.
This website operates from 2012 and it is use for freedom of speech websites, but I didn't compare prices with Njalla, Namecheap and others.
https://flokinet.is/

More alternative that also accepts Bitcoin and cryptocurreny payments for private hosting and domain registration:
- https://xuid.ru/
- https://cheapprivacy.ru/

Few more, but I am not sure if they accept Bitcoin and crypto payments:
- https://www.tonic.to/
- https://www.isnic.is/en