My personal preference would be GitHub flavored markdown, since as a coder it includes a lot of very useful non-standard markups. The compromises it makes on the non-deterministic markup elements are acceptable as well.
Like how they're introducing admonitions syntax by overloading the blockquote sigil that makes it difficult or impossible to nest, has a heavy English bias, and doesn't even transform the underlying element making the use of blockquote unsemantic. They also just skipped the CommonMark RFC and other implementations throwing their weight into the ring with no regard for prior art. I also don't think a corporation, Microsoft, needs to be in charge of the spec either. No thank you.
Many of the GitHub readmes are in markdown already, so people are quite familiar with it and there might already be an open source package that renders it out…
I guess it wasn't clear, but I meant those markdowns are rendered on everyones github page.. But the whole github pages thing is new to me. Very cool and seems like what the blog post was asking for.