For the money, there is nothing in my opinion that can compete with the Fortinet Fortigate line. $1000 or so gets you a hardware firewall with redundant WAN links, IDS, and realtime antivirus at your network's gateway. This company boasts that because they push updates to their devices 24/7, their customers around the globe were patched for the blaster worm within 3 hours of it being recognized. Anyway, I've used the Fortigate 60 for more than one client and have had no issues/problems.
-NeuTron