I'll just get started: I'm a freshmen and so far my hardest year was 7th grade. It got bullied, bad grades, no one to talk to. I'm surprised I even past that grade. This year and last year have been great! I didnt get in trouble at all.
I don't really have a best or worst.
In terms of work 4th and 5th year was the worst because of the amount of classes for gcse's. Was a lot of studying.
This is in the UK so not sure what years that is in US.
Best Years- 7th,8th,9th,10th
Worst-None really stand out as bad years in my head
8th grade. Had a great girlfriend, great friends, but it sort of screwed the future for me in the longrun. I had a new math teacher who didn't have a clue what she was doing so I got a C and was pushed into lower level classes throughout high school, which is compleeeeete BS. Never really got along with my teachers and slacked on my schoolwork, but hey I was young and I just wanted to have fun.
I don't regret it but I'm sure there was a better way I could've gone about it. Since then I've greatly matured, found better friends, and worked myself back up to the highest level math classes. You just need to move on and forget about it, what happened then made you stronger and you stand where you are today because of it.
Well this year probably. It's my Junior year (11th) and I switched schools from a private school to public. It's a big change, and I'm kind of a loner w/ the long hair and stuff. I'm just tired of people thinking I'm guy cause I don't hit on girls and crap.... Anyways yeah. This year.
8th grade. I ruled the school. Everyone knew me, and I was kinda a player. I miss those days 
Best years are my High School years I would have to say. None really was that bad, or I just can not really remember.
9-12 were my best years, the rest were rather boring in comparison.
When I was younger it was best because me and my friend were immature and we were doing a lot of stupid stuff... It was fun! But now we don't do that anymore so it's more boring... I think last year was the most boring for me 9th grade.
All years. Hated school.. Got kicked out all of the time, bad grades, lots of problems, etc...
I had lots of good mates but apart from that, school was terrible for me.