On one episode of 321, they actually were going to give away a St Bernard. Not a toy, not a sponsorship for/experience day out with a mountain-rescue charity or anything - had it not been rejected (which it was in the end), they actually had a real live dog for the winner to take home with them 
Was that the episode that Janice Long and her husband were on? It may have been, although I might be misremembering that.
Best of all was the tie-breaker, where they had to solve the rather obvious clues to find a classical composer - the answer they were looking for was Handel. The first couple guessed wrongly at Mozart and were thus frozen out, just before the final clue, which was "You're sure to know my handle" [geddit?!?!?!] and everybody assumed the second couple obviously had this - before they said Beethoven!
I've just seen that there are a number of full episodes of 321 on YouTube. You'd have to be really sad to want to watch those [note to self: check diary for spare hours].
Sorry to sidetrack - as we were....
Incidentally, does anybody know how the seemingly randomly-chosen celebrities are chosen? Do they apply, are they approached, do the producers stick a pin in Who's Who or what? As for the ones who aren't known as singers: how do they know if the person has a decent/passable voice so that they won't really embarrass themselves, or do they just rely on those people declining - or just not caring if they sound like a frightened fox scraping a rusty anvil across gravel, as long as they get the fee fun?!