Here I'm listing, for my own reference, what I should reinstall when getting a new computer or when restoring an old one. This is an ongoing list, updated as I install new stuff I find worthy.
- Windows. Meh. Then all the service packs available. Meh.
- WinRAR
- An antivirus. Avast?
- Firefox and what I need to get it running
- Chrome
- XAMPP
- Last.fm
- Winamp
- MP3Tag
- Notepad++
- Putty
- TortoiseSVN
- Git and associated stuff for efficient Git setup
- Misc dev stuff: Python, NodeJS,
- Filezilla
- GOM Player
- VLC
- A PHP compiled help file
- PowerISO
- Microsoft Office if the wife needs it
- Photoshop
- SuperCopier
- uTorrent & GreedyTorrent with launcher
- Classic Start Menu from Classic Shell
- Re-enable the Quick Launch toolbar
- Reinstall the printer
- Acrobat Reader
- iTunes (die, shit software) and SharePod
- The webcam
- Skype
- FileSearchEX (search like it's Windows XP)
- f.lux
For a free anti-virus, I'd suggest Microsoft's Security Essentials. I'd say it's better than Avast :)
If you use http://ninite.com, it will save you loads of time too.
I recommend SuperAntispyware for keeping your computer running in tip top shape. It's free and works better than any paid piece of software I've used that is supposed to do the same thing.