Alex Trebek (with ‘70s porno 'stache) – A $50 bill he would relentlessly wave in front of contestants on High Rollers (“Take the fifty! Take the fifty!”)
Devon (Keir Dullea on The Starlost) - The computer that asks “May I be of… assistance?”
Eddie Munster - Wolfie
Joe Friday - Badge #714
Number 6 (The Prisoner) – Lotus 7
Ren and Stimpy – The History Erasure Button or the Don’t Whiz on the Electric Fence boardgame
Rod Serling - cigarette
Any member of the Scott family (The Thunderbirds) - All of the vehicles really, but most especially #2.
In your understandable excitement I think you meant to say the Tracy family. You could add Brains’s big specs, and Lady Penelope’s foot-long cigarette holder.
Star Trek: In terms of the Spock character, I would say the tricorder. I can remember several episodes where he uses that with its postage-stamp-size TV screen. I guess that I’m just not big enough of a fan to recount the episode(s) where he has a slide rule.
The Beverly Hillbillies: The truck.
Green Acres: Lisa’s hotcakes.
Get Smart: The shoe phone has already been mentioned, so I’ll add “the cone of silence”.
I’d say Charlie Brown is more strongly associated with his iconic yellow t-shirt with the black zigzag. That’s how Quentin Tarantino invoked him in Kill Bill.