OS X Disk Utility shows more data
Both Disk Utility and About This Mac use spotlight data to categorize the used space in terms of classes of data:



You can use Finder to search for items using the same classes:



Some notes:


type in the search box the text: kind:movie (as you type look for the hints as the system shows you possible values of kind)
choose list view (the four lines icon top left)
control click and add size so you can then click it and sort by size


You can save this "smart folder" or add a filter like size > whatever limit you want so you can review all large movie files or just all large files.