The adverts - most of them. Do they really think it is OK to bash our ears and eyes with such puerile rubbish, in order to sell us things we don't need, with money we don't have? Junk food, luxury cars, investments, more insurance, even more junk food. Sometimes I think that any single batch of adverts between programs could be used as the opening chapter of a futuristic dystopian horror novel.
The film, The Wicker Man horrified me, as did my favourite Doctor Who scary enemy, the weeping angels. Who can look at a statue in the same way ever again??