rbf.io Machine Learning
This course provides a broad introduction to machine learning, datamining, and statistical pattern recognition.
The whole course can be followed completely free of charge online but the optional certificate of completion has to be purchased.
This already famous introductory MOOC on Machine Learning was first taught in 2011 and led to the founding of Coursera itself. It was my first proper MOOC and enjoyed it a lot. The required weekly commitment including the programming exercises was between 3 to 6h.