<p>While common sense is the best defense against viruses, it’d be quite reckless to go without it. You never know when you might get unlucky, or there’s some odd security hole that gets exploited. Although anti-virus may have it’s faults too, it’s a good second line of defense.</p>
<p>However, I wouldn’t be paying for one. I’ve been using Avast and AVG free edition (both of which are free for personal use) for serveral years, and they’ve been reliably keeping my computers running virus free and at tip-top performance; that is, just as fast as they were when they were brand new.</p>
<p>Oh yeah, don’t forget about anti-spyware. They’re not quite viruses but pose just as much of a problem. If computer viruses are comparable to getting a cold, spyware/adware is comparable to having annoying friends that seriously disrupt your life. Again, I recommend some free tools: AdAware and Spybot.</p>
<p>Just get Microsoft Security Essentials. AVG has sucked for a while. Symantec and Norton I wouldn’t touch with a pole because they sucked for the past decade and I could care less if they improved now.</p>