I've got a few to share.
In year 4 my teacher seemed to hate me and would single me out as much as possible, when very nearly every other teacher I've ever had considered me one of their brightest and most well-behaved pupils. The most memorable event being where the girl sitting next to me kept stealing my pencil case, I would reach over to take it back and she would immediately take it again. The desk was facing the teacher and she had a clear line of sight, so there really should have been no ambiguity about this. She was reading something out to the class at the time and suddenly stopped to shout at me, not both of us, just me, demanding to know why I was disrupting her lesson. I said that the girl next to me kept taking my pencil case, so the teacher made a big song and dance of taking her outside the class and came in five seconds later saying I was the one doing it and that my parents would be called.
In year 7 a science teacher gave my entire class detention in which we had to write lines ("I will not disrupt the lesson.") because one person kept interrupting her.
In year 10 another science teacher gave us some group work to do and told us to form groups however we wanted and do the work, then left the room. When he came back in fifteen minutes later I and one other person were sent out because we were A) not sitting where we were before, and B) talking (about the work). He was fired five years later after growing slowly more and more unstable and unreliable (although it took his entire A-level physics class complaining repeatedly, apparently teachers with physics degrees are hard to find and so the school was reluctant to get rid of them).
Between my years 11 & 12 my school's art photography teacher went part time, this meant that people who had chosen to do A-level photography, having done the GCSE, were mixed into A-level fine art and graphics classes because he only worked enough hours to teach GCSE photography (it was in high demand because he was a thoroughly brilliant teacher in every possible respect, honestly the best teacher I've ever had). We worked on all the same themes, but unlike the graphics and fine art students, the photographers like myself had little to do during the lessons (photos of the inside of a classroom being a somewhat limited prospect) and the attached dark room only being usable for black and white film, which only one person used. This wasn't that bad as the few photographers used the class time to write what little there was to write for the projects, however the teacher (who had no experience with photography) kept insisting that we should do more 'artistic' work in class, every single lesson she would walk over to the table where the photographers sat and made some comment to this effect, this would get murmurs of agreement and then she would shuffle off back to her desk or to check on someone else's work and we would ignore what she said because it was pointless. During one lesson, instead of the agree/ignore response that had become habit I pointed out that we were photographers and so there was basically nothing 'artistic' we could do in class, her response to this was to suggest that we should draw pretty borders around the photographs. Either she missed the point so hard that she accidentally hit someone in the next county, or she wanted us to waste our time with useless busywork to make her feel better. Needless to say I ignored her suggestions.
