I use a mixture of Cloudflare and Porkbun.

Cloudflare offers domains at cost however there are a few caveats:

- they don't support all TLDs

- they require use of their own nameservers

- in order to transfer a domain from one Cloudflare account to another, you have to transfer it to an external registrar first and then transfer back in. A bit bizarre

I still like Cloudflare though :)