When I used to record Endsleigh League Football Extra in the nineties, there used to be some right dodgy adverts when it was on very late on a Monday night like 'Chataway' (0891 181818), "Don't be bored, call friends on '0891 Twenty-seven, Twenty-seven, Twenty-seven!" I could be watching with the volume turned down and these adverts would come on the telly loud enough to wake the dead.
I Remember Peter Cook as E. L. Wistey doing adverts for Watneys beers back in the 60's. Couldn't find any remaining video of them but someone has put this on YouTube, from an old promotional audio flexi-disc (remember them). The ad at 2:28 was always my favourite one.