When i used to teach magic to others, id always give them my RB vampire deck which was a beast. Id then either use my UG trample which stood a chance, or if i knew theyd be a good sport id use my red win and keep board wiping till i was board then deal like 90 direct damage ending their hopes.
But i was always sure to give them a great deck to play thats easy and fun. It was my deck though and i knew every play they could make and how to destroy it.