Sixt was the only rental car option that appeared for Union Station in Denver. Apparently, they had just opened that location a few days prior to my planned trip. I had never heard of this rental car company, but they seemed to have some good deals on luxury car rentals and their website appeared legitimate enough, so I gave it a try. Although they need to work on installing more prominent signage (new location, so it's understandable that they don't have street-visible signs installed yet), I had an amazing experience once I found the place. The check-in was friendly and painless. I got the quality level of vehicle I expected (compact luxury SUV), and it was in excellent condition and clean. The service was impeccable during both pickup and drop-off. I had planned to return the car late on Thanksgiving day, which I am guessing forced an employee to hang around until my scheduled vehicle return time. Their effort and commitment to customer satisfaction was above and beyond any expectations or prior experiences I've had with other companies. In summary, Sixt is a bold new entry to the US rental car market, and they seem to be doing things a bit differently. They offer top-notch quality luxury vehicles at surprisingly affordable prices, and the personalized service and attention to customer needs is absolutely unparalleled. I hope to see Sixt take over the languishing rental car industry, as they deserve to. If Sixt is an option where I am traveling, I will choose their service above any other, every time.