If they're flying in, there are several rental car companies with locations at the airport. Mostly the big box types: Hertz, Enterprise, etc. I can't remember which one I used when I first flew to town to check out the university. They're all about the same anyway.
Today I will do what others won't, so tomorrow I can do what others can't.
Enterprise had the best price compared to another one or two car rental places I called, BUT when they kept asking if I would pay by credit card, not debit card, I wasn't thinking clearly. (In my defense, our van had just broken down and I was a bit flustered.) I thought, of course, our debit cards work as credit cards! We can pay.
Without a credit card payment though, they wanted a credit application filled out. Oops. I did not have any of that kind of information on me. I did have a credit card which we were able to get to work, but it took some finagling due to a bunch of details I won't go into here.
The guy at Enterprise was super smooth and nice about the whole confusion and was pretty smooth and calming to my flustered self. You see, we were late picking up someone at the airport who had been traveling over 26 hours, Paul was waiting for me in another part of town, outside in a hot parking lot; AND we were late picking up 60 pounds of frozen meat. I was just a little stressed! And the delays in getting the payment to work weren't helping! I felt like an idiot not clarifying what the guy on the phone had meant about paying by credit card, not debit card, so I did apologize several times for being clueless about that.
When we returned the SUV after using it to carpool workshop attendees for a week, the check in was smooth, speedy and no hassles!