What antivirus is better?

Microsoft Security Essentials>

I believe that G Data is at the top. http://www.av-comparatives.org/images/stories/test/ondret/avc_fd_mar2012_intl_en.pdf Though it caught the most malware at 99.7 % it had 13 False Positives.

Norton

think no more, bitdefender is the best!!! It has won the maximum number of awards in comparison to any other antivirus. also, the latest version is available at $19.99 (normally $79.99). http://www.softwarereviewsforum.com/antivirus-internet-security/bitdefender-antivirus-sale-89.html you can also read detailed reviews on the mentioned link. i have been using bitdefender since years.

If only every computer user in the world would install antivirus software, the Internet would be a safer place. Botnets would only infest systems whose antivirus definitions hadn't quite caught up, meaning they would never achieve the massive reach necessary for DDoS attacks. Fake antivirus (scareware) threats would lose the ability to make money. Given the quality of free antivirus tools around, there's really no excuse to do without. Here's a run-down on your choices. Cleanup-Only Tools Some free antivirus tools are very specifically designed to root out tough malware infestations. You bring in these tough tools when a virus gets past your regular antivirus, or when malware blocks the installation of security software. The vendors admit that these aggressive cleanup tools have a slightly higher chance of damaging valid files. Otherwise they'd simply roll the technology into their everyday antivirus solutions. Possibly the best-known cleanup-only tool is Malwarebytes' Anti-Malware Free 1.51 (free, 4 stars). More than once when I've had trouble installing an antivirus product for testing, the vendor's tech support agents have recommended a cleanup with Malwarebytes to solve the problem. You might think that Norton Power Eraser (free, 4 stars) is only for Symantec customers; you'd be wrong. Anybody can download and use it to clean up stubborn, persistent threats. Norman Malware Cleaner 2.1 (free, 3.5 stars) differs from the rest in that you burn it to a CD and boot from the CD. In theory this should give it greater power against malware that has infiltrated Windows; in practice, not so much. Our Editors' Choice for free cleanup-only antivirus is Comodo Cleaning Essentials (free, 4.5 stars). It's a little hard to compare the four directly, as Norton Power Eraser was tested with a different set of malware samples. Still, with 91 percent detection and an overall malware cleanup score of 6.8 points, Comodo seems a clear winner. Comodo looked especially good against rootkits, the most persistent threat type of all. It scored 8.7 points for rootkit removal, which is the second highest score in all recent products, both paid and free. Norton scored 6.0 against rootkits, which is not too shabby. Malwarebytes turned in a dismal 3.6 points and Norman brought up the rear with 2.4 points. Full Protection Seven other free products offer full protection, both cleaning up existing threats and using real-time protection to prevent new infestations. Here again a direct comparison is difficult because some were tested using an older set of malware samples. Some vendors of free antivirus products go along with the yearly update cycle typical of commercial products; others don't. Avira Free Antivirus 2012 (free, 4 stars) and AVG Anti-Virus Free 2012 (free, 4 stars) both detected 88 percent of the current set of malware threats. Avira scored 6.7 points while AVG scored 6.5. However, Avira committed the faux pas of identifying a PCMag utility as active malware, and AVG scored better against rootkits. The chart below shows malware blocking scores for all the free products. To understand how I derive these scores, see How We Test Malware Removal.

Norton is utterly worthless in my opinion and Microsoft is just cumbersome and clumsy. I much prefer Malwarebytes to be perfectly honest. But it often takes a combination of security tools to protect my PC. While it's true that having more than one antivirus installed on a computer can often be counterproductive, I've found that having a combination of one program from virus scanning and another for internet security works best. I personally use McAfee Site Advisor for surfing, and Malwarebytes for scanning and constant monitoring.

Microsoft Security Essentials

Go for Avira or Kaspersky. Both are excellent.

Microsoft Security Essentials is much better. Personally I use Trend Micro Titanium Security, for a cheap $25, it's my favourite one