The first and second images are what Mac is saying while the fourth one is what I actually have. This is seriously bad that I can not download anything. Any idea why?
Omni Disk Sweeper is good. I also use Disk Inventory X. You fire it up, it scans for 10-20 minutes (I have a 1TB drive) and then you get a visual representation of your files. It's pretty easy to spot where the pigs are. Select the rectangle of interest and it will tell you the name and location. As noted above, be careful not to delete any system files (which are a different color anyway).