If you're just talking about "the basics," wouldn't the Windows firewall and your standard router be considered the basics? Isn't the router better at staving off much of that stuff anyway?

My complaint about software firewalls is that all the ones I've seen are far too in your face. It's one of the reasons I try to get Norton off my clients' computers, because the built in firewall tells them about every single little occurrence, and it gets to the point where the user is just so fed up with it, they either start approving everything (making the firewall useless) or denying everything to be safe (which breaks a lot of good programs, including AV updates).