Personally, I agree with it is more about your internet etiquette than antivirus or firewall. There is more of a scare tactic by the industry as a whole, supported mostly by a lot of IT professionals who don't work on network security. You do not need an antivirus or firewall. Use CCleaner once a week up to every other day (I use it when I "shutdown" for the night), use the registry scan portion of CCleaner as well as the normal cleaning portion. Unless you elect to click on/open something you do not trust, you really don't have much to worry about. It is a big industry of wasteful money that has an interest in making people think that going online you need "protection". LOLZ, first thing you learn in security, there is no such thing as "unhackable", there will always be new virus's/worms/malware released and you pay companies like Norton's to simply find it and release an update before you have a chance to stumble upon it yourself. Really, if you are always downloading from unknown sources, are opening email attachments you don't recognize, then yes, you need a antivirus and firewall.
Also, as long as you have your OS disk, you can recover from a horrible worm/virus within a couple of hours, worst case scenario. So, want to go to that untrusted site and download a lot of videos? Might get a virus, and the only thing the firewall or antivirus will do is warn you it thinks its hazardous to download (which, you should of known yourself since you are clicking it).
And finally for extra reasoning, these programs take up processing power while constantly running in the background. These are resources you can instead push towards cranking your games graphics. It is a horrible, fear driven market that actually has little need but high demand. Stop buying into their "the internet is dangerous so let us protect you" crap, companies should be the only customers buying firewall/antivirus software, for the most part at least, IMO.
[Edited by Mitchelllucas, 11/3/2014 7:13:04 PM]