I could probably think of a million.
Little bit of a content warning up front (mild abuse, and language).
I was what, 10 years old, in 6th grade? I remember our teacher had a chalkboard up in the classroom on day one (this was around 1992) that said in big letters "THE I AM RETARDED CLUB", and if you didn't do your homework, or you were screwing around in class, or you got in trouble at recess or whatever, your name would go up on the "I AM RETARDED CLUB" board and you wouldn't be allowed to participate in Gym class, recess, field trips, etc. You got to do homework while everyone else was doing those more fun things. Well, #1, there was enough outcry from our class, that he had to change the name to the "I MADE IT CLUB", which didn't change anything else about it.
I remember one day sitting in the hallway doing homework while gym class was going on (I was in the I MADE IT CLUB), and my friends and I snuck into the gym and hid behind the big curtain that divides the gym, and my teacher spotted us and came up and with all his might started kicking at the curtain til we came running out. Anyway, that teacher was reprimanded and ended up getting laid off at the end of the school year after being at that school for almost 20 years. I think one of the kids parents took some legal action when he started kicking. My parents were more of mind of "you probably deserved it". Anyway, times change. He didn't. He would throw chalk brushes at students that weren't paying attention, and in general, didn't have a good disposition for teaching.
My other brief story was in Christian Ethics class in 12th grade (yeah, I went to Catholic school), the teacher made us watch the movie Beaches with Bette Midler, over the course of three classes. It had nothing to do with the class. Dude was just lazy and wanted a movie that he could fall asleep to, which he did, so none of the class paid any attention to the movie. On the second day of Beaches, the guy next to me started chopping up lines of speed on his desk, and we took rails of speed of his desk in Christian Ethics class while the movie Beaches played and the teacher slept. That's the only thing I remember about god damn Beaches.