since i love kicking up dead threads, i'll add my 2cents.
nod32 is among the top rated, alongside windows xp built-in firewall, and i cannot think of once where i've had ANYTHING get passed.
i admittedly (only because everyone does, whether they admit it or not) browse pron sites and other sites that no doubt are full of crap (i do a lot of research for my projects, i follow any possible lead no matter how shady the site looks), and haven't caught anything.
i am on my mac right now, but on windows i always keep the updates fresh, for windows, firefox, nod32, spybot, pretty much everything.
i download stuff all the time, and conduct regular scans.
i have a few other programs that i use occasionally just to verify that my choice software works, and only once did they find something, but it was a tunnel package or something that piggybacked a piece of software i had downloaded a couple months prior, it was on my external.
pretty much set up with good software, dont rely on anything microsoft (use firefox instead of ie, thunderbird instead of outlook, openoffice instead of msoffice), and be a little selective in where you browse, and you wont have any problems.
its worked for me for the last couple years. whenever i redo my system (osx or windows) its because i'm bored