>i'm thinking AVL trees is a good one...
I can give you some recursive insertion and deletion code if you want. Pretty standard, nothing tricky as long as you don't consider the entire algorithm tricky.
I'm still toying with using it in my own AVL tutorial, but it just strikes me as too hackish, and I'm too lazy to write something more elegant. I'll probably end up using Knuth's insertion algorithm and leaving deletion as an exercise.
