When I go through Enterprise, I always return the car with more gas than what I got it with.

I always go through the same office and they usually treat me well...well, except the last time when I got chastised because I made a last-minute reservation and didn't like what they had to offer me (PT Cruiser...ick...not my favorite car...plus, they're uncomfortable as hell for me) and I had to drive across town to get a replacement.