I have to name a couple. When you've gone to school constantly until you were 25, you have a lot of great and bad classes/professors.

In high school, my favorite teacher taught my favorite class: AP English. We had such a great time; I even took the class for two years because that's generally what the AP students did (one year for AP Eng Language, the other for AP Eng Lit, though I'm pretty sure the AP tests themselves were largely indistinguishable). We read interesting books, had great discussions, and the whole class got along really well. We also had the most memorable field trips of my grade school career, week-long trips to New Hampshire/Massachusetts (for the transcendentalists) and to Key West, Florida (I went to a private school so we could do fun things like that). My teacher was a little crazy in that she believed firmly in ghosts (and had previously interacted with them) and other superstitions, but she was a great teacher and a great person.

In college I had another professor for two classes, US Legal History and Criminal Justice, which were two of my favorites. In the former we had a mock trial which was great fun, and the latter was my only A+ in college. The professor was a hilarious and very intelligent guy, and really made you think. One of the only college professors I would just sit and chat to. He probably had the most impact on me of anyone in college, as he really made me confident about law school.

Honorable mention: my law school Criminal Law and Criminal Procedure professor (and his classes), who was amazing. For example: for Crim Pro, he showed us the season 5 opening of The Wire. He made me really want to do criminal defense work.

As far as worst classes and worst professors, I can name it in one: Property in law school, and the professor for it. My god, was that an awful class. First off, real property law is one of the worst of the "main" legal subjects to study. It's archaic and arbitrary and is basically a caricature of the law. And the professor didn't make it any better. He was boring and loved to pontificate on random, useless facts, and so made it impossible to pay attention for any length of time. I just browsed the internet and g-chatted with classmates.

(Dis)Honorable Mention: First Amendment professor, who was so old and senile and apathetic that he was literally incapable of teaching anything. He didn't get "worst," though, as I felt free to ignore him or not even show up for class, and I got an A.