list all files, by size, larger than a specified size?

I am running out of space on my system drive (120GB SSD with < 6GB remaining). It happened in only 12 months. I'd like to know where all that space went, which files are using it. So I'm looking for a way to rank files by size regardless of their folder location, largest-to-smallest, ideally without a full scan of the disk if there are internal indexes that have this info.
Thanks

P.S. Sometimes Windows seems confused. Microsoft Money Sunset edition is taking up 23TB, for example.

This application should help you find what programs are using the most space.

ShowSize Disk Space Analyzer - CNET Download.com

Scan your main drive root directory and you can then open up all the sub directories and it will list how much space each sub is using.