I don’t really watch YouTube while I’m waiting. The only place I have a significant wait time ever is at a doctor’s office, and I wouldn’t watch YouTube there because that would mean other people were being subjected to my phone sound playing.
But every night, when I go to bed, before putting my sleep and wind sleeping sounds, also from YouTube, I always watch some videos.
I like clips from Whose Line is it Anyway, preferably the ones from Drew Carey’s years. I will often watch trailers for movies coming out this year if they look like something I would be interested in. I’m kind of a geology / volcano nerd, so I’ll watch videos about upcoming volcanic eruptions or other geologic events, or ones from historical events. There’s also a number of short films, a lot of the times horror related, although nothing too gory, that you can watch and some of them are pretty brilliant. Sometimes stuff will come up from particular musicals from the past that I like to watch. Those are the main ones that I can think of, but I’m always finding something or other interesting that comes up in my feed. Did you want links, because I can look up a few, but that would probably take a while and you can probably find a lot of this stuff by just doing a search.