By selecting a drive on the left pane and sorting by file size you can get a view of all items on your drive regardless of the directory they are located on. Sorting by folder size gets you an overview of where the big files are located and the number of files in any given directory. There are also options to filter by file type or only analyze files larger than a specific size, making this a really useful tool for cleaning up your drive.
If you are looking for something a bit simpler, Primitive File Size Chart is also a great alternative that is both free and requires no installation – just point to a directory and results are returned within seconds in a plain list detailing the path, name, and size of your largest files. On the other end, you could give Xinorbis a try, as it offers a more sophisticated mix of graphs, tables and tree displays to give users a complete detail of the contents of a hard drive or directory.