While there are many options available, we recommend Cloudflare and Google DNS in that order.
If you're running a cPanel+WHM server, then you can make the changes to /etc/resolv.conf through WHM > Resolver Configuration.
Cloudflare public nameservers
Google public nameservers
Please note that any you pick-up via DHCP should be considered untrusted. Every server should have known good resolvers configured.