I don't know if the name Lois Duncan rings a bell for you, but her books were all the rage when I was an adolescent back in the early 80s. She wrote teen horror novels that were genuinely freaky. I think they appealed to girls more and I have a vague memory of my sister getting them from the library and me reading them. She also wrote "I Know What You Did Last Summer" which got made into a series of teen horror flicks in the last few years.
Killing Mr. Griffin is about a group of high school students who get together to kidnap and scare a really severe english teacher. The tale is told mainly through the eyes of a square loser who gets coerced by the cool group because she won't be suspected. Of course, as suggested by the title, the plan goes too far and the teacher dies.
It's funny because before I started reading this book, I felt a bit cheap about it, like I shouldn't count it as one of my fifty because it wasn't that long and written for teens. But it actually took me a while to get into it. I'm just really not interested at all in the insecurities of teenages, especially girls. I wasn't when I was a teenager (not to say I didn't have them!) and I sure am not now. But once I got into the story, it went very quickly. It's well-written, clear and straightforward, though in a manner that one might associate with a book aimed at teenage girls (very direct emotional exposition). The characters are actually quite good. Each of the teens is slowly revealed, as well as the family around them. Their motivations make sense and nobody is really annoying or stupid. And the narrative moves forward. It's gripping. Though it all wraps up neatly, this almost seems like an afterthought, as everything really goes to shit in quite a nice way. You sense that Duncan prefers the chaos and impending doom to the happy ending.
What struck me most about this book is that it didn't pull any punches. The teens drink and smoke weed, without a big deal being made about it. Bad stuff happens and nobody is blamed. Duncan seems to be saying that bad shit can happen and it can be impossible to avoid. She doesn't waste any time moralizing or making her characters struggle with moral dilemmas. They make mistakes but you can see that it would have been almost impossible for them to do other wise. I have no idea what modern day realistic fiction teens are reading today, but I have this suspicion it is watered down and compromised with morals. I know that fantasy is back in a big way and it is too easy to avoid real harshness in that reality. Something about these teen books from the 70s were really hardcore, like Roger Cormack and SE Hinton (though she was really the one that started it all probably). I remember seeing them for order in those Arrow or whatever catalogues we used to get and feeling freaked out by their toughness and adulthood.