I've been using Kaspersky now for over a year and am very happy with it. It's only caught something one time, but I don't really go anywhere that I feel I'd be very likely to catch a virus. One thing I think is also a positive, is they update virus definitions very often, like every few hours, so you should always be able to have the latest updates available soonest. I use Kaspersky Antivirus and Antihacker and am very happy and will continue to use it.
I can also say, I used AVG for a long time before Kaspersky and didn't have any problems with it though, I just wanted what most all reviews say is the best, so I went with Kaspersky.
Edit: You can download a trial version and see how you like it.