Some sort of Hardware firewall is the best setup. Software firewalls are ok, but can be a pain. You don't really need one if you keep your machine patched and up to date. You really need to be stingy as well on what you download and what emails you open. I still use a firewall mainly for curiousity. To see whats coming in and out. I've found the DoS attacks have somewhat subsided. I used to get the odd attack and used the logs the firewall logs as evidence. All i see now is the odd nimda probes etc... So overall, if you are going to do the odd surfing,etc... and dont keep your PC turned on 24/7, then no, you shouldn't really need one. Just remember to keep your OS up to date with patches and be careful of what files you open as they could contain trojans etc...