500gb hd here with 283gb to spare
Just the games i always play are on 4 all up, rest is apps/usual software MS office etc., some music, a folder with all the DL mods.
When i use to run fraps i didn't know the gameplay movies i would take were so large when i checked the files they added up to 22 gigs of the stuff so dont use as much. Gone back to camtasia studio.
A 500g will last me a while