1. DNS/PublicDNS

https://blog.thousandeyes.com/choosing-public-dns-resolver/

DNS/オープンリゾルバー/公開リスト

Free and Public DNS Servers /lifewire https://www.lifewire.com/free-and-public-dns-servers-2626062

Best free and public DNS servers of 2018 https://www.techradar.com/news/best-dns-server

Open DNS http://www.opendns.com/ (Cisco ?)

Google Public DNS http://code.google.com/speed/public-dns/

DNS/OpenNIC

http://www.networkworld.com/article/3194890/internet/comparing-the-performance-of-popular-public-dns-providers.html

We tested 10 of the most popular public DNS providers:
Comodo, DNS.WATCH, Dyn, FreeDNS, Google,
Level 3, OpenDNS, OpenNIC, SafeDNS and Verisign.
[Disclosure: Verisign is a ThousandEyes customer, as noted on their official website. 

Akamai などの CDN用のDNSとの相性が悪いので、こんな提案もある。

http://googlecode.blogspot.com/2010/01/proposal-to-extend-dns-protocol.html

2. 公開情報

http://pcsupport.about.com/od/tipstricks/a/free-public-dns-servers.htm

3. Public ?

Public DNS Server List http://public-dns.info/nameserver/jp.html

危ない: https://public-dns.info/nameserver/jp.html