u guys should go with AVIRA , im a long member from hackforums.net , and every selled virus/keylogger get anytime dedected from avira but not other progs.
Hello Iam using Microsoft Security Essentials, Which we get from Microsoft for free with every Windows, But certainly You need a Genuine Copy of Windows... Its nice and free, so i prefer it, and the next choice is NIS which i used earlier, i got a Oem version with my Computer, but now its expired so now i use Microsoft Security Essentials...
Norton Products are available for free download (90 days trial), check them here axleration.com/download-norton-internet-security-2011-norton-antivirus-2011-norton-360-version-4-0-for-free/ and I use Norton from Symantec
AVG, and MalwareBytes as a backup. I actually think MalwareBytes is the best, as far as finding and removing viruses and trojans. Norton and McKafee both suck.
The antivirus software I am currently using is AVG free version but I also use game booster for a higher performance and Advanced Systemcare 3 which is also very amazing for cleaning Trojans and other viruses and optimizing your PC.
I like Avast. Here's an article they put out recently about how fast, accurate, and complete it is: http://www.avast.com/pr-fast-accurate-and-free
Let me tell when I used NOD32, I found it most powerful , but it not even leaves system files sometimes to be cured, resulting in crash of windows, my another choice is Norton.