I mostly watch self-development content, whether it's a book summary by FightMediocrity, a motivational video by Elliot Hulse or Tony Robbins, a social or confidence oriented video by one of the RSD folks like RSDTyler, something more spiritual like InfiniteWaters, or something else entirely. There's so many great self-development channels on YouTube, and it's why I run one myself - my passion in life is improving myself, and helping others do the same. So I love any chance at getting tips, and ways to get ahead of myself and improve faster.
When I'm taking a break to relax and not work on improvement then my main go to is gaming channels, some comedy oriented like Galm, Seananners, Chilled etc, some more story oriented like Cry, and others especially RPG oriented like Gopher or SorcererDave.
Occasionally I'll just check out some comedy/prank type oriented channels, but I'm a fan of new stuff that's not been done quite so much before, like HoaxHotel, who specialises in prank calling scammers.