Cloudflare is the most compelling registrar out there today because they don’t charge any markups. It’s cheap AF. You can register or renew a .com for $8.03/yr and get whois guard included. Nobody else can beat the price for renewals — they charge the ICANN fee and that’s it. Want to be even cheaper? Register a domain at 1&1 and then transfer it to Cloudflare. It just can’t get much better.
I think the most compelling thing about Cloudflare is the integrated CDN and SSL certificate management that are available in the free-tier. Again, they’re really just a step above. The free-tier CDN literally makes your site work faster on client systems and it doesn’t cost anything. What’s not to like?
I’ve long been annoyed with the gimmicky nature of registrars. They bait you in with a $1 registration and then try and slam you with $18 renewal fees. It’s just a bad business model. Cloudflare doesn’t make anything on the registrar game — they want you in on the CDN so they can provide add on value later on. It’s a really nice ecosystem and I highly recommend it for the value and performance.