Q: 40 GB of Other and no idea what it is

Hi. So, I've spent a few hours trying to figure out why I have so much space taken up in the 'other' category (I also have about 10 extra gb under movies as well). I've used Disk Utility, I've done the whole reindex under spotlight thing, and I've gone through my computers looking for any giant files. There are none. Help would be greatly appreciated. I've got a macbook pro under el capitan.