From what I can see...graphic design and website development are very popular across the globe and not surprisingly Asia(India) has a very active freelance community. Virtual assistants are being utilized more and more and becoming more versatile especially when it come to wordpress implementaion
Off the top of my head, I'd probably say programming by a margin over web development. With web development, plenty of clients really only need what you can develop from a WYSIWYG editor, and looking at some of the proposals on sites like Upwork recently, I think that's starting to be reflected in the price. I'd follow that with graphic design, because there seem to still be a good number of clients who understand the skill level involved (unlike with content writing or social media management).
I've gotten so good at content most of NY older clients just reg the domain name and send me the login. Once you know how to fill out a WordPress you just have to find other ways to make the content appealing and entertaining. The trick sometimes is holding back a client from adding every bell and whistle. I guess website development for domainers is what I do best.