I personally use Zone Alarm Internet Security Suite. I've been using it for around 2yrs and can honestly say I've not had any major issues. As soon as a bug tries to get in, ZA boots it out! GUI is simple and user-friendly and the app is lite on your system usage. You'll find find a lot of ppl use the ZA firewall as its free and reliable. I opted for the suite to have one complete piece of kit. ZA pretty much gets on with the work "so you don't have to".
Hope this helps.
