First, I am a NOD32 reseller and am biased towards NOD32.
I clean infected computers all day that have Mcafee and Norton. NOD32 lets some spyware by, but that's about it. The performance hit by NOD32 is minimal. I will admit that the latest version of Norton has fixed it resource heaviness. I clean infected computers and then sell my customers NOD32. Uninstalling anti-virus software is a joke. I have to use removal tools for Norton, Mcafee and AVG because they don't want to go away. AVG half the time breaks the TCP/IP stack and Norton leaves behind a service in the network card configuration that until removed breaks your internet.
All personal firewalls are junk. Why do you need one? If I installed a personal firewall on my customers' computers they wouldn't be able to use it from confusion. They ask, "should I allow 'msimn.exe' or is it a virus?" I then tell them to just click "allow" and you'll start getting email again. Then it's downhill from there. They click "allow" for everything including viruses and spyware. Windows 7's firewall is pretty slick for laptops anyway, allowing you to have things open for home or the office and closing things down for public use.
I setup hardware firewalls for my corporate clients, small business and home users. NOD32 and a hardware firewall is all you need.
I don't know if this is allowed... if you go to nexgold.com and put in my name "justin" for the discount code you'll get 5% off of NOD32.
I rate anti-virus software in this order:
2. Microsoft Security Essentials (because it's the best free AV)
3. Kaspersky (It's just as good as NOD32, but uses way more resources)
4. Avira (free AV that uses very little resources, gives too many false positives)
5. Norton (last year's version would be last on the list)
6. AVG, Macfee and the rest (AVG was once my favorite, now they are junk)