My original anti-virus program was a total fail, so I was in the same predicament you are in.
My two choices were AVG and Avast!.
At first I went with AVG, but I within months of using it, I got a virus and it wiped my HDD.
After I reset EVERYTHING, I tried Avast!. I've been using Avast! for over a year now and I haven't had a problem yet.
