'Best' can be a subjective thing. For instance, I like my Hertz service as my name is on the board, and a car is waiting for me, usually some sort of superduper upgrade. But your Hertz experience could vary - you may not like the bus ride, and if you don't have Gold membership you could be waiting in line for some time. Therefore my 'best' experience may not be your 'best' experience.
Others may find National 'best' - while I am an Emerald customer, on a few occaissions there have not been cars in the garage, so I still had a wait.
Generally,
Alamo and National have membership options which allow you to bypass the line, and are onsite, which MAY result in quicker departure.
However, as we see here all the time, service may vary from any agency, resulting in delays getting to your resort.