I have been running a public DNS server for private purpose (never liked my ISP’s DNS servers, and the root servers were usually located too far away (at least those with easy to remember IPs).
Anyway, been testing it since this summer, and so far it’s been working great.
IP address: 18.104.22.168
Might not be an easy to remember IP address (unlike 22.214.171.124), but as I use that IP pretty much every day, it’s okay for me. 😉
Edit: Let me remind you that I do not agree with NX domain hijacking, or falsifying/redirecting certain DNS requests (such as OpenDNS google.com to google.navigation.opendns.com or the Belgian ban on stopkinderporno.com and redirecting it to 126.96.36.199).
Check out this awesome tool to find the best DNS servers near you.