There are quite a few competent antivirus applications.
AVG, however, has chosen to partner with ask.com and provides an ask.com toolbar whether you like it or not (the so-called "linkscanner").
Some other antivirus and spyware providers remove ASK toolbars as spyware.
We at the forum remove ASK toolbars whenever they are installed otherwise.
What does that tell you?
Most of the forum helpers use Kaspersky, Avira Antivir, or Eset NOD32. Microsoft's Security Essentials is OK too, as is Avast!.
There are a number of competent anti-spyware programs, but the best right now is Malwarebytes Anti-malware.
The free version is an on-demand scanner. The paid version runs full time and is cheap (lifetime).
You should be sure you have a limit of ONE antivirus, and ONE anti-spyware, that run full time.
You may use a second anti-spyware if it is only an on-demand scanner.
The third party firewalls are beginning to cause more trouble than they are worth, and if you have a router at home, not necessarily useful.
The exception is for a traveling laptop, where the extra protection (Online Armor, Outpost, avoid others) may be worth the nuisance.
(These are my personal opinions and observations only.)
Good job, and good luck.