What is the best website to look for the cheapest airfares?

There is no single website that is always best for airfares. It's useful to use the sites that will search across several of the other sites. A couple of useful ones are: a href="http://www.kayak.com/" rel="nofollow"http://www.kayak.com//a and a href="http://www.skyscanner.net/" rel="nofollow"http://www.skyscanner.net//a