Talk about loaded questions. When it comes to A/V software, you'll find everyone has their own opinions on what's the best. Norton probably has one of the best detection engines out there, problem is its become so big and bloated over the years that it also reduces system performance by 20% or more. The latest Norton 360 isn't quite as bad in the resources department, but it is still a bit of hog. If you want the absolute best protection, the Norton product is your best bet.

If you want top notch protection, but also don't want to slow your system down significantly, you can't beat Avast. Clocking in at between 2-4% system resources, Avast is very light on performance, unless its actively updating at the time, during which time the system will slow a bit. But this only occurs once a day for a minute or two, you'll get the message that the definitions have been updated and things go on as normal. Now with the latest update to 4.8, they've added full root-kit detection and removal as well as spyware protection. Avast looks to be placing itself into a position to supply full PC security and not just A/V. Definately one to watch and I recommend it to all my customers who do not currently have an up to date A/V program installed. - Free for 14 months at a time and it works well.

Kaspersky is another one which is pretty good, not quite as light weight as Avast, but has a great detection engine. I'm in the fence on this product. Good detection with decent resource requirements, however it just doesn't seem to have the polish of some of the others.

Just my $.02 worth on the subject. For the money, you can't beat Avast. Several of my corporate customers have even switched to their Professional version with good results.

When it comes to anti virus softwares everyone thinks differently. Every one's opinions are different. Well, here is what I think.

I have tried McAfee, Norton, NOD32, and Kaspersky. Each one has ups and downs. McAfee consumes a lot of cpu resources like RAM. Norton is same. NOD 32 is not that good when it comes to identifying viruses. Kaspersky is again like a combination of NOD 32 and McAfee.

Now I am going to try AVG 8. It is the new version and I hope that is better, because every one recommends AVG over many other virus guards.

It depends on what you want, really. The best free one in my opinion is AVG anti-virus in my opinion, as it's fast, easy to sue, and best of all, free. McAfee, I find, is one of the worst anti-virus softwares availible. It is slow, uses up a lot of ram, takes ages to load, treats the user like an idiot, and worst of all, once, when I was using the program WPE, a packet logger, to test one of my programs, it gone and deleted WPE without my permission, saying a "threat" had been "cured". Norton is slightly better, but still poor. Other smaller anti-virus programs are usually okay.

Sorry, that just made me chuckle.

On a more serious note, AVG updated to 8.0 recently, including the free anti-virus. I can't say I've personally noticed any changes, but I figure they updated it for a reason so woohoo! I do like how they keep hinting at you to go for their more expensive (i.e. not-free) version, though, cunningly hiding the free alternatives away in corners of the page out of people's way. Still, I guess they've got to make money some way so good for them.

if you mean whats is the best free av s i would say AVG and Avast .. and the best pay av s Kaspersky and Eset Nod32 .. thanks to everibody ...

this maybe different, but i've tested almost every antivirus, and the result is that none of free antivirus-es could beat the payed ones. you may use any of them, but believe me, it's very risky if you are only depending on it (except there're not much activities around your computer such as connecting external storage device (flash disks, bluetooth, phone cable, etc.) and downloading. oh, even when you're in some chat room you might get some virus contained ads, right?).

The best anti virus
What Is The Best Anti-virus

Replying to Takumi-sanReplying to Takumi-san
I think the best anti virus is Kaspersky
Http://mylifewithcomputer.Blogspot.Com/2008/07/internet-security-70.Html

-reply by adri

The best anti-virus is ESET NOD32 then Kaspersky. NOD32 is the only anti-virus that got an Advanced+ rating in tests conducted at http://www.av-comparatives.org/

The most popular free anti-virus programs (AVG and Avast) have poor detection rates (82.82%, 87.46% respectively). Norton is notoriously bloated and takes forever to perform full systems scans.

I only recommend buying NOD32 (advanced users) or Kaspersky. It has been proven these products are better than the best sellers (Norton and McAfee)

I prefer Eset Smart Security(think NOD32 + firewall + antispam) for the all around protection, it is lightweight, has a awesome firewall, and is very easy to use.
My second would be Avast!4 as it is free and supports themes(which is great if you have a custom desktop), they also have a Linux client out, which is good cause as Linux popularity increases more and more viri writers will start targeting it for their new viruses.

I would also agree with these. I've also used kapaskery antivirus and Norton on my mac. An old uni friend use to recommend using the panda anti-virus (you'll have to google it). I think it has some license thing which means you can reuse it on other machines, thus saving money.