Well, in spite of RTI's typical delusional posting, in this instance about how Norton is often "turned into a big Trojan" I'd going to give a huge should out here for the CURRENT VERSION of Norton AntiVirus. I used to absolutely despise Norton as it was very intrusive and a huge memory hog. I then read Daniel Tonks talking about how good the current version is and did a little research and decided to give it a try.

First off you literally don't even know it's running it is so lightweight and they have a neat litte meter that shows cpu usage. The interface is also quite good. overall I prefer it to eset which is what I used in the past. Highly recommended. You can also but a 5-user pack for only $89. And if you do a search on "coupon codes" on Google and look up current codes, should should be able to save about 20% on whichever version you buy.