This tutorial is responsible for my start in C# programming. For me personally, I find implementation-first learning (i.e. being told what to do to get something functioning first, then retroactively learning the principles from working solutions) to be the most effective and this definitely implements that well.
One major drawback is that it teaches using the somewhat obsolete Windows Forms API from the .NET framework. I personally love this API but from a utilitarian and professional standpoint there isn't much point in learning it unless you're going to maintain very specific legacy systems.
I'd be dishonest if I didn't acknowledge that the UI of this website is heavily based on principles I picked up from this tutorial. Somewhat lacking in HTML and CSS knowledge, I needed to learn to use a robust and reliable UI framework that I could easily implement into my own projects.
I found the technical explanations of what was going on to be somewhat lacking, however the discrete and precise modularity of the implementation allowed me to get a decent grasp of how to translate the principles to this website.