I am an Avis Preferred Select. My rental agreement is always waiting, just have to show a credit card for verification, and the car is always close to the counter. I get the infrequent upgrade, usually when there are no cars left in the class that I rented. I also get a price break (most times) and always get unlimited miles.

I get the same treatment with Thrifty Quicksilver although I do not use them as often (maybe 10% of the time).