Kid channel, some sims will get bored or upset if I remember right, it depend on traits, I think it was a snob or materialistic one.
The humor channel increase comedy skill and give a playfull moodlet.
I think the sport channel give an happy or energized moodlet to sims with the bro trait, if they look at it with other bro.
I usually don't have a tv in my sims houses, so I don't know much about it.