This class was one of the early courses with online videos and materials. I think this will be great if you are interested in learning about convex optimization in some detail. This class will be on Stanford's OpenEdx platform with new materials.
Dan Boneh is teaching a two part sequence on cryptography:
The practical exercises in part I worked through defects in the implementations of cryptographic protocols. If you want to really understand how some of the popular crypto algorithms work, these two courses will help you.
Introduction to Databases: https://class.stanford.edu/courses/Engineering/db/2014_1/abo...
Internet History, Technology, and History: https://www.coursera.org/course/insidetheinternet
CS169x SaaS - https://www.edx.org/course/uc-berkeleyx/uc-berkeleyx-cs169-1...
I'm planning on taking:
Design of Everyday Objects
Mobile Web Development
Design of Computer Programs
And maybe one big data topic.