You should check travel websites such as Kayak, Hotwire, Expedia and Priceline as well as agency websites like Hertz, Avis, Enterprise and Alamo. Compare their rates for their most basic, economy-size cars. Find the best deal for your location and the period of time in which you'll need a rental.
In the majority of situations, you're best off sticking with one of these agencies, as they are the most widely used and reputable: Advantage, Alamo, Avis, Budget, Dollar, Enterprise, Hertz, National. Before you decide on an agency, look into and/or ask about their additional fees. These fees can change what agency provides the best deal all things considered. Some common fees include:
Underage-driver fees: Additional charge for a driver under 25. Airport surcharges: Additional charge for picking up a rental at the airport. Mileage fees: Additional charges for going over a certain miles per day cap. Additional driver fees: Additional charges for having more than one person drive the rental.