It really depends how much you want to spend.
Only keep one virus protection program loaded because if you have more than one loaded they may conflict with each other.
Sometimes stores (BestBuy, Circuit City, CompUSA, etc.) have programs like Norton and McAfee for free after mail-in rebate. One of those should be enough for the regular computer user. I use AVG Free by Grisoft (www.grisoft.com
). I like this one because its free and it doesn't cost for the updates. I know that after your subscription expires with Norton, usually one year, the virus updates aren't available until you renew it. I'm not sure about McAfee.
If you have a lot of personal information on the laptop and are willing to spend $30 dollars, I hear good things about pctools.com virus protection program (http://www.pctools.com/anti-virus/
). I've also heard good things about Panda Software Antivirus, costs around $50 for one year.
Hope this helps. Just a few options that I know about.