None
I'd say that's probably one of the best certification I can get.
I learn everything by doing. I'll give you a very recent example: if I want to learn how interpreters and compilers work, I don't go to class and waste weeks or months getting lectured. I take one day off and make a simple programming language instead. Now I know the basics, and I'm slowly learning how to compile this language into the CLR.
That said, if you're looking for a good CS class, I'd wholeheartedly recomment Structure and Interpretation of Computer Programs. If you follow the link you'll find downloadable video lectures from 1986. They're old, but what they teach would change any non-functional programmer's perspective on programming forever.