Media: Songbird, VLC, Handbrake, DVD Flick
I’ve been using VLC for ages, and it does everything I need as my video player of choice. Audio duties I leave up to Songbird, which has matured into a fantastic application over the past two years. I use Handbrake to, uh, rip my non-encrypted, personal DVDs. DVD Flick lets me burn said rips back onto a disc.

File Transfer: Free Download Manager, Cabos, eMule
FDM is a very underrated torrent app, and it has plenty of other download-boosting abilities as well. I chose it over Vuze because FDM has extra features for partial zips, Flash downloading, Rapidshare integration much more than Vuze’s additional media-handling chops. Cabos trims Limewire down to the bare minimum for the occasional one-off Napster/Gnutella download. As for eMule, I normally use it to find things that I can’t find elsewhere.

Imaging: ZScreen, Inkscape, Gimphoto/GimPad, Flickr Uploadr
If you’re comfortable with Photoshop but looking for a free alternative, go with Gimphoto instead of Gimp – the interface is very Adobe-esque as it is a modified version of Gimp. For vector image jobs, Inkscape can’t be beat. ZScreen handles my screen captures and Flickr Uploadr, well, it does what it says.

Burning and Backup: Infrarecorder, WinCDEmu, Bonkey, and DirSyncPro
All the first three apps above make short work of mounting disc image files, burning just about anything, syncing folders, and keeping a current copy of your files in a safe location.

Messaging and Social Networking: Pidgin and Spaz
Well I know Spaz is built on Adobe Air, but the client itself is open. As for multi-protocol messaging apps, Pidgin is a tough bird to beat.

Maintenance and Utilities: 7zip, Belvedere, Ultra Defrag, Disk Cleaner, TrueCrypt
Lifehacker’s Belvedere is a great way to organize your files and folders with minimal effort. Ultra Defrag and Disk Cleaner (and a handful of helpful plugins) keep your hard drive clutter free and performing its best. 7zip is an alternative for Winzip and WinRar which waits in your context menu to extract files from (or cram files into) archives of all kinds. For encrypting files, folders, or entire volumes, Truecrypt is fast and reliable.

Desktop Enhancements: RocketDock, Launchy, Virtual Dimension
You don’t really need both RocketDock and Launchy. If you prefer eye candy, go with Rocket Dock. If you’re a keyboard magician, go with Launchy. Virtual Dimension is a pretty cool app which gives you a full-featured virtual desktop manager on Windows based PC’s.

Games: AssaultCube, Enigma, FreeCiv, LexJongg, LinCity, Neverball, Nexuiz, PokerTH, TORCS, Tremulous, WinSudoku, Wormux, Zombies.
Your computer shouldn’t be all work, all the time. There are times which you need to kick back and relax or give you brain a casual workout with these great games. LexJongg puts a slightly technogeek spin on traditional mahjong. FPS fans should check out AssaultCube, Nexuiz, and Tremulous. FreeCiv and LinCity offer OSS takes on two classic PC simulations. TORCS is a solid 3d racing sim which will hopefully soon include online action. Wormux and Zombies are fun turn-based strategy games. WinSudoku and PokerTH – well the name says it all, so I assume you know what those are all about.

Well, there you go – plenty of great open source software (OSS) to load on your own freshly reinstalled system or an already in use system! If there are any apps that I missed out, maybe some of your favorite apps or games, share it in the comments!