What are a few top cheap travel sites?

There are a lot of cheap travel sites. Some include Travelocity, Priceline and Orbitz. However, these "Big Box" travel comparison sites are actually rarely the cheapest. They actually have overhead, costs they have to cover for advertising, huge staffs, etc. Think of a store in the mall. The price is higher because the store pays higher rent to be in the mall. Smaller stores outside the mall will always have lower prices. By far the cheapest travel site I have found is Rate Rhino (see the related weblink below). This site has no fees, and has proven for years to be 20-40% less than any of the sites most people visit, such as Expedia.