War of the worms is a wonderful explanation for why so many of us have so many emails generated by worms such as Bagle.I, Bagle.J, Bagle.F, Bagle.G, Bagle.H, Netsky.C, Netsky.C and MyDoom.F, MyDoom.G.
"We suspect that several virus authors – or factions of virus authors – are competing in creating the most successfully spreading worm. So far we see three different groups or persons..."
To help protect yourself from viruses, worms and hoaxes visit http://www.sarc.com/ to confirm all warnings before ever forwarding a message onto other people; frequently the threat of a virus or a virus hoax generates more email than the actual virus.
Here is a nice list of antivirus solutions. I cannot vouch for how current or accurate the information is.
I personally use Norton Antivirus (be aware they have many different versions: pro, corp, etc) and backit up with TrendMicro's online scanner. I also recommend McAfee, Doctor Solomon(appears to be McAfee now) and I have heard great things about f-prot.