Things my kids never used:
Electric hairbrush
Electric knife
Polaroid Camera
Plastic cover to make BW TV look like color
Walkman
Pong
Record player
Reel to Reel
Oven cleaner
Electric cords made of cord
Party line phone
Lighted princess phone
Tube tester
Wooden screens
Growing up, I loved Reel-To-Reel, I was so good at spooling it, my Dad would call me to do it. The sound was fantastic.