Well,
My recommendations,
If u want protection for free then you have
1. Avira personal edition
2. Grisoft AVG free edition
3. Avast home edition
Otherwise if u wish to pay then,
1. Kaspersky internet security (I use this and im extremely satisfied, im a heavy downloader and really happy with the protection)
2. ESET nod32 antivirus or smart security suite
3. Bitdefender total security/internet security (maybe a resource hog)
4. Avast Professional
5. Norton internet security 2009
the choice is upto you, remember you're protecting ur digital world.