Less Wrong articles categorized by reading difficulty

One thing that could help new users dive into Less Wrong would be to make some reading recommendations based on reading difficulty. (I’m including some things not hosted on LessWrong.com when they’re very LessWrong-ish and written by leading LessWrong authors.) For example:

For everyone

For those with some math and statistics
For mathgods
Now, I ask: What are some of your favorite articles in each of these categories?