8.8.8.8
8.8.4.4
2001:4860:4860::8888
2001:4860:4860::8844

Contra: Google is logging your location and your IP for up to 48 hours. So go better with a DNS Server from OpenNIC.

1.1.1.1
1.0.0.1
2606:4700:4700::1111
2606:4700:4700::1001

85.214.20.141 (FoeBud)
204.152.184.76 (f.6to4-servers.net, ISC, USA)
2001:4f8:0:2::14 (f.6to4-servers.net, IPv6, ISC)
194.150.168.168 (dns.as250.net; Berlin/Frankfurt)
213.73.91.35 (dnscache.berlin.ccc.de)

More DNS Servers:

• https://www.opennicproject.org
• http://dnsrec.meo.ws (OpenNIC)

Sources: http://www.pcworld.com/article/183671/Google_Public_DNS_and_Your_Privacy.html