Fred Putnam (who is currently on faculty at Philadelphia Biblical University) is one of the most energetic teachers I have ever known. I think he maintains his slender physique by the vast amount of energy exerted from his very animated (literally) teaching style. He obviously loves what he studies and teaches and that enthusiasm leaps out of him. He is also quite generous with sharing his work. Check his website www.fredputnam.org for some very beneficial resources.
Fred is one of the most well-read people I know. His musings on literature always inspire me to add yet another book to my reading list. Oh, and he loves to play with Ankerstein blocks. What more could you ask for?