Best: When I was in 3rd, 5th, and some parts of 7th grade. Kick ass teachers, work wasn't that hard, it was just <3333.
Worst: 4th, 6th, first half of 8th, and 10th grade. In 4th grade, my teacher was an 80 year old bitch and the work was next to impossible. 6th grade and first half of 8th grade...teachers were cool, but it was just so much drama and BS peer wise. 10th grade...living hell. Gets my vote for the worst schedule I've ever had for classes. (Though being in an overcrowded school doesn't help much either).