I use cloudflare and it's great. It feels like the only registrar that has a business case for at cost domains. Also if you're worried about cloudflare downtime, you can only use them for dns resolution (which hasn't been impacted) and not for proxying.

I've used a bunch, but Namecheap is the easy go-to for me today. Their support is extremely good. In over ten years, we've never had an issue that we couldn't solve over chat in 15 minutes.