Here's a ranking of free online language courses that made it to the front page of reddit today. Most of them appear to have a Chinese course.
I'm only familiar with the MIT courses which I have been using to get my grammar fix and add a little more structure to my Chinese studies. I think they are pretty well done; I don't know about the other courses mentioned in the list.
Also, here are the comments from the reddit post (ChinesePod does get a "shout out"):
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