I've used this module on every single site I've built since discovering it. I love the way you can just create stuff using HTML and just put them anywhere in the site. It's very simple to use and if you're smart in the way you write your HTML you can practically put as many of these as you want in one page - with each one controlled by its own CSS.
I was looking for a nice menu that I could fully customize using its .css file without any complications or difficulty. I tried a lot of em before I came across this one and I must say I'm really impressed.