A Saturday night institution in Switzerland, as well as Germany and Austria, the show is famous for featuring members of the public performing bizarre or outrageous stunts, and at its peak attracted up to 25 million prime-time viewers in Germany, making it that country's biggest TV show in history.
Its swansong was no exception, with Stiller gamely helping out as a blind 18-year old attempted to fit missing jigsaw pieces into a gigantic puzzle using a form of human radar — the acoustic echo from the gaps — to deduce the shapes.
Stiller's forfeit would have been to sing Jingle Bells — a fate he was spared after the contestant, Dave Janischek - managed to get all three pieces correct.
Earlier Stiller wiped Leberwurst from the face of another presenter, following a stunt in which a blindfolded seven-year old boy managed to deduce the identities of five dogs — from a possible 22 — just from the way they licked the Leberwurst off his hand.
Stiller was the last in a line of A-list Hollywood stars to participate in the programme, often somewhat awkwardly, as most relied on simultaneous translation through an earpiece to know what was going on.
And even then they could look perplexed by both the German sense of humour and the bizarre stunts.
Other stars to have appeared in what Will Arnett called "that crazy German TV show" include Tom Cruise, Harrison Ford and Cameron Diaz.
Wetten Dass . . .?, which means "Want to Bet That . . .?" was hit by tragedy four years ago when a contestant was paralyzed in front of a live studio audience and millions of viewers when a stunt went horribly wrong.
Samuel Koch was attempting to leapfrog over a moving car using stilts, but instead hit the car head on and collapsed to the ground motionless.
Cameras cut to the shocked audience whilst an ambulance was called, and the transmission abruptly ended.
Koch suffered life-altering injuries, being paralyzed from the neck down, although not, as first feared, brain damage.
In a further twist, the car was being driven by Koch's father.
Long-time presenter Thomas Gottshalk left the show shortly afterwards, and it struggled with decreasing viewers under new host Markus Lanz.
Koch himself made an emotional return to the show on Saturday night, receiving a minute-long standing ovation from the audience, before detailing how he has rebuilt his life, and now works as an actor.