This one is tough to nail. See the below links for criteria required to have one awarded. There have been "4,698 episodes (as of 27 August 2012)"
Blue Peter is a British CBBC children's television programme. First aired in 1958, it has become the world's second longest-running children's television programme behind Sooty.
https://en.wikipedia.org/wiki/Blue_Peter
The badges were introduced to the programme by editor Biddy Baxter in 1963, from an idea by Blue Peter producer Edward Barnes. Except for the "Gold" badge and the pre-2005 "Competition Winners' Badge", the badges are in the shape of a shield containing the Blue Peter ship logo, designed by Tony Hart.
https://en.wikipedia.org/wiki/Blue_Peter_badge
Blue Badges are awarded for sending interesting letters, emails, stories, pictures, poems, good ideas for the programme, and for having appeared on Blue Peter.
