Not many surprises here. Firefox is #1 and the list includes a number of excellent programs. I use 7zip as my default zip program, Gaim (now called Pidgin) as my default Messenger and Syncback runs every day to back up my work PC. I have used and like Picasa & Notepad++ but I prefer Notetab Light. Foxit Reader is an excellent alternative to Adobe Reader and a much smaller download.

In addition to these I also use and recommend

AI Roboform - website password store

Utorrent - Torrent download client

Mozilla Thunderbird - open source mail client - much better then Outlook Express

Gmail - for online email access and enormous email store

AVG antivirus - free av program with low resource

What free software do you use - email and let us know

LH Top 10: Free Windows Downloads - Lifehacker