A very attentive customer service. Not only that, they are very kind and helping. They always try to find you the best offers.
Also, all the cars I rented are brand new (2014-2015)
One notable thing is that I forgot my USB Mp3 player hooked up in my last rental and they called me, right after they dropped me off at my place, and said that they will leave it at the front desk for me to pick up...