The most fun robots can be those built by amateur robot builders. This is an extremely innovative space.
Robotics always had a home in education, with academic builders using them for learning and experimentation platforms. Many commercial ventures have started in this setting. University robots tend to be group efforts, with access to increasingly hi-tech academic equipment to create them, as shown in the following picture:
Kismet was created at MIT in the late 90s. There are a ...