T-Mobile G1 / HTC Dream (2008)

The G1/Dream (sold under both names) had one major innovation for the future of smartphones: It was the first phone to offer Android OS. Google had bought Android several years earlier, with plans to focus on creating an operating system that facilitated all kinds of mobile tasks. This particular model was the first sign that they had succeeded in a big way, ultimately leading to the formation of the Open Handset Alliance.