There is no single 'type' that is better than anything else. What works the best though is when someone presents something new and never before seen... whether that be a stylistic approach or simply footage/personality etc that we've not seen before. Different can be better than being better.
For those providing entertainment consider YouTube today's version of the reality TV show. You can come here to get an actual glimpse into someone's life. Educational content is also in very high demand and the beauty of it is that you have so many different personalities to choose from.
What is important though is to not focus on what is best for YouTube... figure out what is the thing that is best for you so that you can give the best presentation possible to your audience.
I think there is an audience for all types of videos. Finding and connecting with the audience is the trick. I could not make videos 'just for the views'. If I do not have any interest in it, I think it would show in the video. Make videos on what you are passionate about, and with a lot of work, and even more luck, you might make it.
Smaller genres will have fewer potential viewers, but also maybe fewer channels. There are some genres that seem more popular, but they are also saturated with channels - getting traction is still a problem. My wife wants to make a channel, but she is shy of her English, and wants to speak a mix of Kiray-a and Tagalog. My first thought was that most of the world speaks English... but then again, there are 100 million Filipinos. If she could just get a fraction of those...
There is an audience for whatever you want to make.