I know about Google DNS and open DNS. I will say few things regarding those two DNS.
Google DNS: Google operates the world's largest public DNS service. Launched in December 2009, it supports many billions of DNS queries per day, much of the volume generated from clients outside the U.S. Google Public DNS utilizes servers at IP addresses 188.8.131.52 and 184.108.40.206. The company developed this service as one of its corporate initiatives to make the Internet more accessible and easier for everyone to use, making it a logical choice for users worldwide.
Open DNS: The oldest of all services on this list, OpenDNS also supports billions of DNS queries per day via its servers operating on 220.127.116.11 and 18.104.22.168. In addition to its basic name resolution service, OpenDNS Home Solutions provides free Web site filtering of adult content (called FamilyShield) and URL spell correction with accompanying installed software. The company also sells various security products to businesses. Those looking for an alternative to Google products and a service that works well outside the U.S. also tend to like OpenDNS.