Udigrudi recommends Futurelearn

You can follow me on Future Learn to find out what I've been studying and what I've been saying in class.

Now, I don't finish all the classes I start, but I do finish quite a few.  I've learnt how to cook for a medieval king, how to find a spleen on an anatomy chart, how to prevent the spread of the Ebola virus, and I'm beginning to learn how to make a musical instrument out of javascript.

The most fun I've had was making the Plantagenet pie, but the discussion has been illuminating.  Students from all over the world, many of whom teach the subject in school or even at university, share insights on topics that they are expert at.

And, some of the world's most renowned experts actually teach the courses.  I shared a link to the Battle of Waterloo with a Waterloo tour guide, and the guide actually heard of the instructor, saying the instructor was one of the best known experts in the field.

Try it out.

I've also found great courses on Coursera and EDX, and both have excellent courses, but I find communicating with other students easiest on futurelearn.

I've also tried FUN, the French site.  There are a few good courses there, but they are very time limited.

Futurelearn has courses from Korea, New Zealand, the UK, Israel, Holland and elsewhere.