What seems to be most popular are posts about Crypto currency. But I'd really encourage you to branch out from that. The community needs to, it can't just be an echo chamber talking up how great Steem and Steemit is. So explore, try different things. Share knowledge. You never know what might catch someone's eye. I tried a few different things and only recently felt rewarded for it. I wrote a book review. Something I had never tried before, and people liked it. I had no intention of writing book reviews when I got started on Steemit. But I read a lot, so now in retrospect it almost seems obvious that I should focus on what I like. You ought to do the same.