I have been using avg antivirus free edition 9.0 it has been good as I know. You could download it free online.
mm maybe check this out? http://www.av-comparatives.org/images/stories/test/ondret/avc_report25.pdf Its an anti-virus comparison done by an independent organization/company/people. So Supposedly there's been no bribery from other companies to boost up their marks. I'm using AVG free 9.0 right now... The trial version state lets you try out their internet security and various other random stuff for 30 days. I'll likely switch to another once the trial is up though. It seems AVG's been bashed here as being nub antivirus =P Anyway, I'm also using CCleaner and Microsoft Defragment/Austologics Disk Defrag combo (Austologics by itself takes forever in arranging and re-arranging the same things over again. Microsoft one takes care of that). It seems to do the trick in keeping things nice and tidy.
oooooo ... the good old 15 posts, sure brings back memories =D *no flaming intended, it's just nostalgic.
there isn't a "best" out there, is more like a preference... out of the free ones, msft essential, avast, avg... and the paid ones, panda, eset, norton, trend, etc... there are pro and cons of each... i still like trend best, company uses it and i bought trend ever since... mine is the pro version where i have access to who is trying to add to my network to parental controls with password protection on changing settings...i also use opendns to replay my dns severs by mine isp because i can also customize on what categories can be blocked etc the non pro version is about $10 per PC per year... before trend and if you are like me, reinstall OS every year to get rid of the crap, you don't need any antivirus/firewall/spyware remover...esp w7 comes with creating an image to restore anytime, that saves a lot of time
I use AVG and I am happy with it. Another alternative is AntiVir...But I don't like it since it always pop up some advertisement.