Google Open DNS which provides greater speed, but not always true for everyone. The speed of the DNS is dependent on many factors such as, for example, from the particular routing used by your provider and where are the sites that usually sail.
For choosing the right DNS propose then the program Namebench which will check all sites that look ii frequently, using the cache of your browser or Alternatively, the first 10,000 sites in Alexa rankingAnd compare the time spent using the most common DNS, the test takes to run about ten minutes at the end of the test will automatically open the browser with a page containing lots of information that include highly detailed graphics on the same page Namebench advise you which DNS adopt.
Namebench is available for Windows, Linux and Mac, requires no installation: just specify the IP addresses in the program on which to test and you will get the results.