Geoff Hinton's 2012 Coursera course "Neural Networks for Machine Learning" was incredible. Anyone who took that course got in on the ground floor of deep learning just when it was about to take off. It certainly changed the course of my career.

To give an idea of how cutting-edge it was at the time, the well-known RMSProp optimizer was unpublished work that Hinton presented in the course, and people had to cite the presentation slides when they used it in papers published later.