I started taking Udacity online courses last month. The first class I joined is Intro to Statistics, and so far so good. The reason of choosing Statistics is I had never taken any proper statistics course back in college.
Compared to Coursera, I like Udacity more because it makes learning more fun, whereas Coursera is more like proper university training. On Udacity, the teaching staff created a nice web interface so that you can even practice programming exercises (mostly python) on the web.
Just this afternoon, I learned how to plot scatter plots, bar charts and histograms by using Python matplotlib, which was a lot of fun!