In high school, Mrs. Moore. About 70 in 1970 and taught humanities. She was approx. 5' 2" and 80 lbs who commanded respect and most of all taught me how to read, enjoy, and make the classics from Plato to Joyce relevant.
In College my Major advisor, Dr. Macior who was a Jesuit, who expected his students in his office for lunch whenever possible. He quizzed us on our views on everything sacred and profane and challenged you on all your beliefs. He taught us to think critically and actually understand why you thought what you did. And he bought us ice cream on botany field trips.
Grade 7, Mr. Tourigny. The first teacher I ever had who really understood the students, and who didn't talk down to us. I don't even know if I can explain it, but you just mesh well with certain people, you know?
I ran into him on the street ten years after leaving his class (which in itself is quite a few years ago now) and he still knew me by name.
In middle school, it was Mr. Santos. He was one of those teachers that you either loved (like all his old students who came back once in a while, myself included) or hated. My last day of sixth grade, which was also the day my grandmother died, stood as the worst day of my life for a good long while.
In high school, it was definitely Mr. Crook. Even though I thought he was an idiot most of the time (and I inadvertently contributed to his getting fired), he got me interested in broadcasting.
"He is the most overrated piece of crap in the league. He bitched and whined after he got his ass beaten in New England last year, so the NFL changed the rules. Then he got his ass beaten in New England again. Every year he's the top MVP candidate. Every year he's supposed to be the best. Every year he's going to carry the Colts to the Super Bowl. And every single year he goes to New England and gets his ass beaten. And his brother's a whiny little bitch." -A friend of mine, on Peyton Manning