“Best” by WHAT CRITERIA...?
There’s 7 billion people on this planet with 7 billion different sets of preferences that could give you 7 billion different subjective answers...
#sex related topics
And many more
I think cryptocurrency is a good subject to blog about. Right now there are not many people blogging about it because of the bear market the interest has swindled. But this will come back, i believe it will become back a hype.
When you are a bit creative, there are a lot of options to monetize your blog.