I see lots of free classes on the technical side of things such as math, science, learning to program, etc.
I would love to learn more about the financial side of things and I don't mean just micro- and macroeconomics. A class that is more practical that teaches you about valuation, reading a statement, marketing, negotiations, etc.
A class in web development just explaining what everything is and what it does. There are a million different acronyms for all the different technologies out there. I look up stuff when I can, but more often than not I just end up more confused.
Some sort of conflict resolution - e.g. a guided roleplay.
I'm not sure. Maybe something like law.
Permission Marketing
Chinese -- it'd be pretty impressive if anyone could pull that off well in a free online class.