Your very own Won't Get Fooled Again in the early stages of Channel 5's The Best of Bad TV: The 70s. You can pretty much imagine what featured here, I expect: various dwarves in rubber suits running around bumping into the scenery in old science fiction series, various crappy game shows with hilariously awful prizes, and some sphincter-tightening sexism and racism from comedy classics like The Comedians and The Wheeltappers And Shunters Social Club.
There was also a spot for the public information film Dark Water: pretty creepy, but not a patch on The Finishing Line. A quick scan of this compilation suggests it's not in the list (it was not a Public Information Film in the strict sense) but there is nonetheless some excellent nightmare fuel in there. Here's The Finishing Line, if for some reason you don't fancy sleeping tonight.