In order to show them to the classic series here is my master plan. You should start them with Robot, and then show them more hinchcliffs. Then expand to the Pertwees (The Daemons, Sea devils and auton ones should prove favorable) and later Tom Baker seasons (City of Death) introduce the odd Davidson, or sixties episode (Caves, Earthshock, Resurection/ The deadplanet, Invasion of Earth, Tomb, and The Mind Robber) and as the furthur along you go introduce them to some bad serials (Timelash and flight, The Twin Dilema, The Rani serials, Mccoy's first season, The Trial.) Try not to show them any ones longer than six parts when starting out, and don't show them any recons either. Finally introduce the good Mccoy episodes and then the rest of his and Collin Baker's too.