Becoming a game-show host can be hazardous to your reputation.

A few days ago BBC Four repeated a fascinating documentary, The Secret Life Of Bob Monkhouse, about the late, great comedian's ups and downs over the decades. Monkhouse was a consummate comic, but switched to scriptwriting and serious acting early on, and is probably best known to generations of TV viewers as a game show host. That was a big deal for comedians back in the 1970s and 80s, but it wasn't all fun and games; and certainly not for Bob.

One of the major blows in Monkhouse's career involved his first big game show job: as host of ATV's bizarre crossbow-and-fireworks accident-waiting-to-happen extravaganza The Golden Shot. He was a huge hit as host, but then - excuse the pun - got fired, due to press speculation that he was a bit too friendly with some of the firms whose products were featured regularly as prizes. Then his replacements - fellow comics Norman Vaughan and Charlie Williams - flopped, and Bob was back.

Game shows needed a savvy comic in that era as the prizes were pretty laughable. Nowadays the commercial channels can get sponsors on board - the popular online gaming site Pink Casino sponsors Channel 5's Blind Date, for example, hosted by Paul O'Grady - and modern game show prizes elicit genuine gasps. Back then it was often an ironic 'ooh' and 'aah' as the glamorous assistants wheeled out a cuddly toy and a teasmade.

It takes real comic skill to walk that tightrope, just the right side of rampant mickey-taking, hence Bob's long career in game shows: he went on to host Celebrity Squares, Family Fortunes, Bob's Full House and the talent show Bob Says Opportunity Knocks, where applauding some of the acts must have been as difficult as talking up those old prizes. There's a great bit in the documentary where he addresses a dinner, and gives a lengthy monologue about the importance of always being truthful. Eventually he hits the big payoff, about sincerity: "if you can fake that, you can fake anything."

Those shows clearly gave Monkhouse a good living, but his real love was comedy: he'd worked with everyone from Arthur Askey and Bob Hope to David Jason and Joan Rivers. So it must have hurt when alternative comedy arrived in the 1980s and tried to flush him away. Anyone who'd taken the light-entertainment game-show route - Monkhouse, Jim Davidson, Tom O'Connor, Jim Bowen - was suddenly an endangered species.

Actually, like most game-show acts, Bob had continued to work the clubs too, even amassing a hefty collection of glasses due to his habit of taking one for the road. His real collection though - and the main subject of the BBC Four documentary - was the comedy he'd recorded over the years, having owned one of the first home video recorders. Indeed, alternative comedy owes him a debt: among his huge arsenal were super-rare audio recordings of Peter Cook and Dudley Moore's show Not Only... But Also, broadcasts that were otherwise thought lost in the great BBC cull of the expensive-tape era.

That collection only fully came to light after Monkhouse's death in 2003, as he'd kept it quiet having gotten in trouble for that too: he was accused of copyright infringement for keeping old recordings, eventually exonerated, but remained wary of letting outsiders into his inner sanctum. Thankfully, while still performing, Monkhouse's status as a comic was belatedly restored too. A new generation - the likes of Kevin Day and Dominic Holland were enthusiastic talking heads in the doc - lauded his way with a one-liner. The game-show affliction was lifted.

Of course, nowadays the short-term goal for many aspiring comics is to appear on a panel show, and perhaps even do well enough to host one. But that's a whole different type of game show, of course. Not so many rubbish prizes.