The original smart phone:
Blackberries used to be amazing phones, and even after iPhone and Android came out, Blackberries were still superior for a few years in terms of features and functionality. They were not easy to use, but they were very powerful and worked incredibly well.
Unfortunately, once iPhone and Android started to gain traction, RIM started panicking and trying to make their phones more consumer friendly. Not only did they fail to gain interest from the consumers, but the changes started alienating corporate customers, causing businesses to move away from the platform.