My laptop (actually a netbook - easier to carry and completely silent) has a habit of killing it's hard drive, so I don't keep anything on it. It's dead at the moment :frustrating:
My PC has all my CD's backed up in FLAC format, all the pictures I've taken since getting a camera and probably a load of downloaded TV series and movies from my misspent youth. Oh, and probably a copy of every version of Windows ever released and many Linux isos dating back 9 years. I really should have a clearout :blushed:
Some pictures (due to working with PS)
Games (Oblivion, Dungeons&Dragons Online, etc)
Aurora Toolset (I'm a NWN builder/scripter).
Programs I need to build sites or databases (I'm an IT)
My laptop (it's a gamer's laptop due to my graphic and CPU necessities, 17" screen and weights a whooping 4Kg with battery) has 2 drives. One is kept purely for the OS and the other is used to install programs and it's where I keep documents, pictures, etc.
Both of them are never full and I regularly do sweeps on them to keep them clean. Once every 6 months, the OS drive is formated and the OS reinstalled from scratch to keep things smooth.
Music, Movies/Shows, Pictures, Games, Adobe Suite, Rhino 3d, and lots o documents from old jobs that I might have to reference in 20 years when zombies take over the world and I want to watch some digital television while I enjoy the last twinkie on earth
I've got a bunch of pictures (mostly my wedding ones and then I dump off my phone each month or so, wallpapers, a big collection of gifs... I'm on tumblr and reddit to much), documents for school, a shitload of music (it's my goal to have a library that can play continuously for a month and have it actually all be songs I know and like). I've got Sims and tonnes of mods for that, Civ 5, and Rosetta stone... otherwise no special software.