Should I watch the Hobbit trilogy before the LotR trilogy?

I’ve read the LotR books and have watched bits and pieces of the new Hobbit movies.

I’m trying to get my son to sit down and watch the currently released movies in succession for a weekend and want to know how to make the most sense of the Tolkien universe and have maximum watching experience.

What is the suggested watching order of all of the Peter Jackson movies, both the Hobbit trilogy and the Lord of the Rings trilogy?