Is it one that you just use and works just fine? Or one that has proven to be reliable and responsible if they do a mistake and only want to satisfy you as a customer?
Cloudflare - largely because they don’t add on extra fees.
Having recently setup an UnRaid server I used a walkthrough video on setting up SSL certs for them through Cloudflare and Google Domains. Was already using their DNS (1.1.1.1) and had an account so made that it an easy decision, then Google decided Domains would be sold off so I fully migrated to Cloudflare. I find the free tier to have more things included than I even understand and it does everything I need.
Also just switched to Cloudflare (used to be google domains)… since they run half the internet, they probably won’t be going anywhere anytime soon? Feels like every service gets sold/acquired and I have to change everything over every few years and I’m getting tired hahaha… also their DNS changes update basically instantly and are easy to do for this newbie!
I personally think it’s better to keep your domain registration separate from your hosting/cloud providers, including cloudflare. Basically not putting all your eggs in the same basket. Those giant cloud companies probably won’t be going anywhere anytime soon, but their automated system are known to ban users with no recourse unless you’re a big spender with dedicated account managers. Having your domain elsewhere means when something happen to your hosting/cloud account, at least you’re not completely fucked.
Heh I was also on Google domains before they announced they were selling it. I don’t know what the hell possessed me to register domains with Google. They have a very well documented history of killing off great services. https://killedbygoogle.com/