The classic "Aurora" Monster kits - you were no-one until you had glued and painted at least one of these models. I had the werewolf one, but it's head, hands and feet were made of pale green Glo-in-the-dark material so it looked rubbish in the day and just weird at night.

We used to hang towels over the garage windows to black out the light, then set up the models along with the Horror mags and Pan book covers (lit with torches) then charge the smaller kids 10p a time to walk though the 'Haunted House".

An added bonus would be to hide under blankets in a corner then jump out screaming at an opportune moment - I think several pairs of pants were ruined this way, not to mention the emotional scarring.