I haven't explored all the lessons here yet, but just off the top of my head I would really like to see lessons on famous/noteworthy
(1) novels (including but not limited to 四大名著)
(2) poems (again including but not limited to 唐诗)
(3) kings
There's just so much that's fascinating and rich about Chinese. After all, we've got 五千年的历史!