The obvious go-to choice was Cloudflare for us too, but then it turned out you can't use CF just as a registrar (at least on the basic plan or equivalent), you need to use Cloudflare's nameservers as well... But we use Google's Cloud DNS for everything, so that was a showstopper. In the end we went with AWS Route 53.
CF could probably get a lot more customers if they would allow you to use custom nameservers for your domain.
CF could probably get a lot more customers if they would allow you to use custom nameservers for your domain.