I had a pretty good experience with Enterprise. They provided me with a car while mine was getting body work. They went the extra mile for me to drop the car off at the body shop, and pick it back up from the body shop once I was done with my repairs.
The only reason I didn't give them 5 stars is the minor issue with the gas when I first got it. Basically, they gave me a car that was running on fumes when I got it, so I had to go to the gas station and play "guess how much gas you use in 2 days".
When I called them the day after, a manager (Frank) heard my complaint, and reimbursed me for the extra gas I left in the tank. He definitely made it right, and I would definitely use them again.
... Except I may call them ahead of time and make sure it is dropped off with a full tank of gas. :)