On: Ask HN: What are the best MOOCs you've taken?

[justinhj]

Andrew Ngs machine learning course as well as both Princeton Algorithms courses were the most challenging and valuable.

I did all the Scala ones a few years ago, the most interesting was building a distributed key value store.

There’s a really online interesting course on Milton at Yale. Great lectures but I didn’t try to work through any of the assignments.

Not really a Mooc but I recommend both Duolingo and Memrise for learning language skills on your phone