For 5 of my 6 years in undergrad I participated in the OSU Robotics Club Mars Rover Team. This was one of the best decisions of my life and contributed almost as much to where I am today as all of my formal education. I firmly believe in a hands on approach to learning, and this was a perfect compliment to all of my engineering coursework. Throughout that time I learned valuable lessons about mechanical design, leadership, project management, and educational outreach.
We were not the most successful team, only placing first once in my time there. However I think the failures taught us much more than the victories. (Even though it was super cool to finally win!)