My favorite for what it does...

There are some other apps out there that do this type of thing and do it very well. However, this one is my favorite for finding what files and folders are taking up the most space on my drive.
I really like the fact that it offers options on how I want to view the information unlike another app that I have that limits me to viewing it in a Pie Chart style.
Its a great app and I would highly recommend it!

Skenzer about WhatSize