The only afterschool special I remember is "The Wave." Does anyone else remember that one? The plot was something along the lines of the teacher showing his class how easy it is to be be seduced into participating in a facist society. He formed a special club and gave students various levels of powers within it. At the end he revealed that he was using the same techniques as Hitler. Only two students refused to join and thought he was up to no good. I am sure I am forgetting a lot of the plot, it was a long time ago.
Not an afterschool special, but a great movie we watched in high school was "Stand and Deliver." YOU. MUST HAVE. THE DESIRE!! Very inspirational, and it actually made me pay attention in math class. Well, for a month or two, anyway.