I'm still using Avira right now, but I'll have to switch to something else soon because they decided to make the new 2012 version incompatible with other software firewalls. They are now forcing you to use their new built-in firewall. I'm using Comodo for that though, and I generally don't respond well to hostile takeovers, so Avira is getting the boot.
That said, I'm open to other firewalls besides Comodo, even bundled ones like NOD32... Does anyone of you who is using NOD know how the firewall module compares? Or are you using NOD Antivirus only, with a different firewall?