Wrong. IMO a firewall is typically a must for a home network. You are just as targeted as a company network and a firewall will help you moniter traffic and the program's that connect outside/inside your computer or network.
ok, let me rephrase that...

I'm not going to install a firewall program... my desktop and other laptop both have firewall programs so i can restrict in/out on those machines. Also, I have a router with SPI, dhcp, and completely stealth (according to shields up!). The laptop won't be online very often, probably just to get other games from the archive.