http://wiki.castlecops.com/Lists_of_freeware_antivirus
http://wiki.castlecops.com/Lists_of_freeware_antispyware
http://wiki.castlecops.com/Lists_of_freeware_antitrojan
http://wiki.castlecops.com/Lists_of_freeware_antikeyloggers
http://wiki.castlecops.com/Lists_of_freeware_antirootkit
http://wiki.castlecops.com/Lists_of_freeware_firewalls
http://wiki.castlecops.com/Lists_of_freeware_behavior_blockers
http://wiki.castlecops.com/Lists_of_freeware_sandboxes
http://wiki.castlecops.com/Lists_of_freeware_virtualization
http://wiki.castlecops.com/Lists_of_freeware_analysis_tools
Above is perhaps the most comprehensive list of top class freeware security products. How do they compare to the best $$ware in each category. If 10 is the best in the $$ category, here are my ratings for the corresponding best freeware. I.e 10 = the best freeware is as good (if not better) than the best payware.
Antivirus 8.5/10 - Each of the freeware antivirus as certain minor weaknesses compared to their paid bigger brothers
Antispyware 8/10 - Most of the freeware antispyware has no on-access scan except Spyware terminator.
Antitrojan 9/10 - Not quite sure, very few self declared anti-trojans these days... Trojanhunter vs BOclean?
Antikeylogger 7.5/10 - Possibly higher if we include sandboxes and behavior blockers against keylogger
Antirootkit 10/10 - The best generic antirootkits are free!
Firewall 10/10 - Comodo firewall , Webroot firewall , Online armor free etc help to raise the score.
Behavior blocker 9.5/10 - Many excellent choices depending on what you are looking for. Eqsecure,threatfire, SSM free, DSA etc etc are all top notch
Sandbox 9/10 - GesWall, sandboxie etc. Also SafeSpace lately.
Virtualization 10/10
Other misc security 10/10
This is just my estimation, what is yours? In short , i believe it is more than possible to use only freeware and remain as safe as one using $$ware only.
, I have used and/or are still using those (as well as others without a