A few quick videos:
Gödel and Mandelbrot
This is an article with a list of very different types of programming language all of which are worth learning: The seven programming ur-languages.
In addition to ALGOL languages (which every one needs to know), check out:
I’m not ready for this, but I wish I was: Post’s theorem.
An intro to category theory: “Categories for the Working Hacker” by Philip Wadler.
I forget why I ran this search, but it turned up some interesting results:
I am not yet ready for Let Over Lambda, but one day I will be.