I tried kaspersky & it was telling me I was being protected from a virus every 30 seconds or so, (Pc-Cillin did the same thing) & that turned me off. There is no way in reality that an average home P/C is getting attacked that often. It just isn't believable, that's when I came to the conclusion a lot of the big AV progs, especially the free scanners, tell you they are doing all sorts of blocking so you'll think "wow this A/V program is GREAT, it's saved me from infection 347 times today alone!"
Nod-32 or Avast if you just refuse to pay $30 for the best A/V program there is...I have heard a good buzz about Bit-defender too, but I have never personally used it.