Easy-way:
Open the program Namebench.
Immediately wrote press "Start benchmark".
This process takes about 12 to 30 minutes.
When finished Namebench will provide the best DNS servers for your computer.
Change your DNS servers.
Restart the connection.
Tadaaaaaaaaaa ..........
DOWNLOAD
WindowsXP/Mac/Linux
http://code.google.com/p/namebench/
Windows 7
https://www.grc.com/dev/DNSBench.exe