I can't help but notice that the great majority of my past professors were skilled at presenting lectures but lacked the essence of what I believe makes a professor/instructor really stand out: ENGAGEMENT.
I can count on one hand the top professors that I have had throughout my college career that have mastered this skill. They are the instructors that make you excited about coming to class. They get your wheels turning upstairs, and you leave simply blown away by how much can be taught in one hour!
As for the others…resorting to expensive coffee with extra shots of espresso and plenty of doodling scratch paper are mandatory to make it through. Going through the same bland PowerPoint lecture class after class (that could have been printed out and studied outside of the classroom) is mindless.
Variety, passion, excellence, drive, enthusiasm, these are just some of the words that come to mind when I think of the very few professors that stood out as master-classes in instruction.