Udacity CS-212
Peter Norvig is a big name in computer programming. I stumbled across some of his code and was struck by how he could often accomplish in 4 lines of code things that might take me pages.
A bit more searching led me to a course taught by Peter on Udacity Design of Computer Programs
There were a number of places where I was absolutely blown away. Almost always it was a case of me over-engineering the problem (usually with unneccesary OOP) where his simple data types and list comprehensions nailed it.