Anyone have a suggestion for the best rental car company?

I am going to be arriving on a Saturday at MCO (Orlando Airport) staying one night on WDW property and then driving to Port Canaveral and return the car.

After the 4 night cruise I will rent another car and drive back to WDW for a few days, then back to the airport.

What is most convenient? I usually use National (I like the Emerald Club... skip the line... benefit) but I can't find them listed near Port Canaveral.

All I see is Budget, Avis, Hertz and Thrifty.

I am looking for the one that is the easiest and most convient... not (necessarily) the cheapest.