Interesting how everyone is naming different types of videos. I guess after gaming there's no general consensus- we only know based on what we've seen because YouTube is so big. Personally I think a lot of them are in essence tied- there are popular people in each genre
Niche travel seems to work well. Disney content works very well for me, because Disney has a very large, dedicated fandom. I think thats why gaming is so popular...large, dedicated fandom. Otherwise, my regular vlogs do really well as long as the topics are interesting.
Beauty product reviews and tutorials do really well. They don't seem to be going away anytime soon.