1. OpenDNS
Primary, secondary DNS servers: 208.67.222.222 and 208.67.220.220
2. Cloudflare
Primary, secondary DNS servers: 1.1.1.1 and 1.0.0.1
3. Google Public DNS
Primary, secondary DNS servers: 8.8.8.8 and 8.8.4.4
4. Norton ConnectSafe
Primary, secondary DNS servers: 199.85.126.10 and 199.85.127.10
5. Comodo Secure DNS
Primary, secondary DNS servers: 8.26.56.26 and 8.20.247.20
6. Quad9
Primary, secondary DNS servers: 9.9.9.9 and 149.112.112.112
7. Verisign DNS
Primary, secondary DNS servers: 64.6.64.6 and 64.6.65.6
https://www.techradar.com/news/best-dns-server