Nod32 is the best that I've ever used
http://nod32.com
It seems like they update their definitions daily, so they're definately on top of things.
I've been through a few programs before in the past and things have gotten through, but so far, Nod32 has been perfect. Like someone mentioned above, they do have a 30 day trial, so give it a shot, I'm sure you'll fall in love with it.