My horror experiences are limited to Alamo, from whom I will never rent again. But I've also had unpleasant experiences with Budget and Dollar as well. I won't go through the details, but as someone who rents a car 5 or 6 times a year, I have settled on a simple plan.

First, I rent only from Hertz, Avis, or National, mostly Avis. Second, I have memberships in Hertz Gold, Avis Wizard, and National Emerald.

And third, I use the discount codes posted in the appropriate forums on this board, and as a result I can almost always get a rate equal to or lower than any of the so-called low-price rental agencies.

The hassles are minimal, the convenience great, the screw-ups rare, and the cost about as reasonable as one can expect.