Ok, I'm sure most of us have had to reinstall windows at one time or other and know how much of a bugger it can be to get things back to how you had it before, so the idea here is to list what programs you'd install first on a fresh setup.
First thing I do when reinstalling is remove the cable connection from the modem, to avoid any possible holes being exploited before the firewall and virus protection is installed. I'd then do this list.
1. SP2
2. AVG anti-virus
3. Graphic and sound drivers.
4. Email (Outlook)
5. Firefox and assorted plugins
6. Video codecs (mega codec pack)
7. VLC video player
That's about all I can think of just now for necessary stuff so if you can suggest anything else feel free...