From what I've heard, as far as firewalls go nothing beats an OpenBSD box in between the interwebz and the rest of your LAN, though I've yet to try it (lack of space, time and money to do so). Still, I do use the firewall on my router, a few tweaks here and there and I've yet to see a problem with it.
Antivirus, I'm partial to Avast myself. Its relatively unintrusive, doesn't soak up resources like a sponge and on my grandma's computer at least it has stopped every virus that's tried to infect it so far, so I'm happy with it. Certainly doesn't arise the anger and desire for violence that McAffee and Norton did, last time I infected my computer with that trash.
Ohhh, and if any of you wants to browse through... err... potentially dodgy websites without risking your precious computer, I'd suggest trying out VirtualBox to run a Linux VM on your machine. Far safer and less resource intensive than running three or four AV programs stacked one on top of another, as I've seen 'out in the field' sometimes.