DiskView plugs into Windows Explorer, and helps you find big files and folders instantly. With the DiskView Visualizer and Folders panes, and the DiskView Toolbar and Column Handlers, DiskView enables Windows Explorer as well as Internet Explorer to graphically show files and foldersI have seen a lot of disk viewing utilities in my day, but DiskView is the best.  It's slick, has an innovative disk space manager, and integrates nicely within Windows Explorer.

I highly recommend you download it and check it out for yourself!