i love the history of television and broadcasting and could watch old footage of news broadcasts and behind the scenes footage of the television industry and old commercials forever.
old youtube home video footage of ordinary people walking in cities or in old department stories is the best thing ever.
Meanwhile I'm interested in the branding of television channels. You know, the actual "art" stuff that screams "you're watching [channel name]" with flashy graphics and a catchy soundtrack.
Here's an example from a channel that I remember watching as a kid that doesn't exist anymore: