What is the best car rental company?

I don't think there is any One best car company. I think the best car rental company is the company that gives you the best rate, on the vehicle that you want for that particular rental. Here's an idea of how to find the best car rental rate. Go to a booking site, like Carzonrent, kayak,Bus moves and check the city, dates, times and car sizes that you are looking for. If there is an option to check both on airport and off airport, do that. Once you find the cheapest company, book the car (as long as it's not prepaid... if you have to give your credit card number, don't book yet!).

Go to that particular company's website directly, first, and see if they have any specials that will help you get the rate even cheaper than the booking site. Try and use a discount code or coupon if you have one. If you find a cheaper rate, you can book it and then go back and cancel the reservation that you made on the booking site. If you couldn't find anything cheaper, then you know you've found the cheapest car rental for the dates you were looking for.