Crystal Maze had Dr. Frankenfurter from 'The Rocky Horror Picture Show'.
Bullseye had Jim Bowen, who always did everything perfectly.

No scandals but mediocre. So many speed boats as top prizes!
Fort Boyard had Leslie Grantham, the murderer and sex offender.
Gladiators had a lot of injuries and wouldn't be allowed in this country any more because of health and safety.
Supermarket Sweep had Dale Winton who killed himself. It was also very cheesy.
Big Break had racist, sexist Jim Davidson.
It's a Knockout had serial paedophile Stuart Hall.
Pets Win Prizes had a lot of pets and prizes but no scandals that I've heard about. I wouldn't be surprised if there was some bestiality going on.
Scrapheap Challenge had Robert Llewelyn, the fake android from Red Dwarf. No scandals except that he got fat and his android costume had to be expanded to fit. Boo! Androids shouldn't get fat!
Anyway, I suppose that Bullseye is my favourite but the others had their moments. Personally, I prefer Transformers movies and shows.