We have used both quite a bit, and I prefer Budget. But they both have pros and cons. Budget tends to have s shorter line (not always true though, depending on how many flights have come it etc.), and they have not been as hard sell on the insurance...at Alamo, they often try to trick you into taking it with verbal games. Some people really like picking their own car, and of course that would have to be Alamo. I've noticed Budget's cars tend to have higher mileage, but we have never had any trouble with them, and they've given us a couple of nice free upgrades. Also, I joined Fastbreak for free, so I can skip the MCO line.
Barb