I teach 9th grade Biology I and 11-12th grade Advanced Placement Biology.  The AP Biology students and I take a trip to the University of Pittsburgh to perform some genetic engineering experiments.  The students get a chance to see what a real college lab "feels like" and they get to do some cool
science with technology.  My favorite teacher was Mr. Tack, my Pre-Calculus teacher in High School.
He was rigorous, fun and made the extra effort to help out a (formerly) math-phobic student so that she not only earned a good grade, but understood the fundamentals of math content.