I don't watch TV to relax, I do it to cure boredom. To relax I sometimes listen to di.fm/chilloutdreams and maybe some other music. (I listen to other music too but usually not to relax.) I used to listen to jazz too to relax but haven't in a while. And sometimes I listen to Lofi on YouTube and just stare at the repeating graphics (e.g. https://www.youtube.com/watch?v=5qap5aO4i9A), they're really good at taking you away..