Media Player
MPlayer

Replaces:
Windows Media Player
Benefits:
- Support for more file formats than Windows Media Player without additional codecs
- Free software
Download.
CD Burner
InfraRecorder

Replaces:
Nero
Benefits:
- Many more options presented in an intuitive way and full progress reports through the burning process
- Free software
Download.
Operating System
Ubuntu Linux

Replaces:
Microsoft Windows
Benefits:
- Free software
- Much more secure than Windows
- Prepackaged with all of the above programs or equally good equivalents, also for free
- Comes as LiveCD: run the full version from a CD without affecting your hard-drive
- Package manager allows one-click full install and uninstall of over 20,000 free programs and games as well as constant automatic updaes of everything on your computer with new features and fixes
- Totally customizable interface and system
- Six-month release cycle
- 3D effects preinstalled
- All of this including 3D desktop at full speed on systems barely able to run Windows XP (256MB RAM, integrated graphics, Pentium III CPU)
Download.
PDF files:
Foxit Reader (Credit to Richard Rahl for pointing this out)
Replaces: Adobe Reader (formerly known as Acrobat Reader)
Benefits:
- faster
- some extra tools that are not in Adobe Reader, but only in it's bigger brother (Adobe Acrobat). However, some of them only work in the paid version of Foxit Reader. But all that makes
Foxit Reader replace Adobe Reader, is 100% free. (sorry for the bad construction of this sentence)
ImgBurn

ImgBurn is a lightweight CD / DVD / HD DVD / Blu-ray burning application that everyone should have in their toolkit! (thank you, Rootworm)
It has several 'Modes', each one for performing a different task:
- Read - Read a disc to an image file
- Build - Create an image file from files on your computer or network - or you can write the files directly to a disc
- Write - Write an image file to a disc
- Verify - Check a disc is 100% readable. Optionally, you can also have ImgBurn compare it against a given image file to ensure the actual data is correct
- Discovery Used in combination with DVDInfoPro, you can check the quality of the burns your drive is producing
Lots off credit to Game_boy. Not a member here to my knowledge....