depents on what content you want to make,
If you make music, then make covers of the current most popular songs or make own songs.
for gaming, pick the new releases, maybe some which is still in alpha or beta state.
For blogging try disguss ongoing events in the world
To name something wich is populair is almost impossible as things become populair once uploaded depending on type of content and such. I have seen simple video's get thousands of views in a matter of hours wich was just a funny video from a cat. The same thing is for music and gaming. It doesn't matter what you upload but how you bring and make the content.
Sorry... to answer your question... Highly edited music videos seem to get the most views on youtube... but that is probably inflated by fake views by music publishers so its hard to say if its true or not
Well, I think anything can be popular on YouTube, you just have to catch the attention of the public[/Q
That's true and i will check out your channel if you check out my channel but only sub if you like my videos and don't forget to comment