I have for years been a fan of Eset's offerings -- their antivirus and then their combined antivirus and firewall.
Before switching to Eset I was a big fan of Agnitum.
From my standpoint, Eset has the best, most utilitarian and powerful user system, as far as user options and interface.
The options and alerts are excellent -- and they still have some firewall features that for some reason few have copied -- like when an alert pops up you can choose to ignore it for the current session (or once, or create a rule).
So many of the firewalls reviewed (and which get good ratings) offer so little control and information. There really needs to be a distinction between truly flexible controllable firewalls like Eset, Outpost, and Comodo, which are in a different class than the others, that just silently do their job and offer you little information or control -- and little help if something is being silently blocked which shouldn't be. It does alert me when anything tries to connect in or out which I like to know.
I love the clean interface of Eset's tools -- and they get just about every single thing right when it comes to organizing and presenting options, logs, alerts, etc.
HOWEVER, I have recently dumped Eset despite being a paying customer. I have confirmed that their firewall makes my computer unstable and causes programs to occasionally hang and require a reboot to terminate. Prior to windows 7, a known and apparently unfixable-by-them bug in their win xp x64 version would cause computer freeze and blue screen when attaching an external usb. This was a known problem for years that i cast a blind eye to. When freezes started happening on my win7 machine, i had enough.
For the last week I've been trialing AVG internet security. I tried a dozen others but AVG was the one that I found least offensive. I might try outpost again, as I always liked Outpost, but right now AVG is doing pretty well by me.
I did not install the optional stuff like web browsing guards, identity guards, etc. -- and thankfully those are optional installs. Those seem too likely to cause problems and slowdowns to me.
AVG does *not* offer the kind of fine granularity control of the powerful firewalls like Eset and Outpost, but it does offer more control and transparency than some of the truly minimal ones. But my patience for micro-managing firewall access control rules has diminished over the years, so that's not bothering me as much as it would have in the past.
In terms of basic antivirus and firewall, i'm not unhappy with AVG, and the system performance and stability seem really excellent, which is my main concern these days.