@Petertree
I think one of the difficulties you are apt to experience in posing your question is the discovery that one person's food is another's poison - where few, if any, of the responders have subjected AV/malware apps to controlled testing. Don't misunderstand, experience is a wonderful teacher but not everyone surfs the Net in the same way, at the same sites, with the same apps.
Many of the apps mentioned here are not met with the same enthusiasm by testing labs which even differ amongst themselves. Regardless, unless you frequent risky sites (torrents, dot ru, XXX, etc.), any of the better known stand-alone apps or suites (Avast, Avira, AVG, Comodo)will serve you well. Basically, there are three walls of protection that I employ: AV (e.g. Avast, Avira, Comodo, AVG, etc.), firewall (ZA, Comodo, PCTools, Windows, etc.) real-time/off-line malware (SpywareGuard, Spybot TeaTimer, WinPatrol, Malwarebytes, AD-Aware, Windows, etc.).
The best thing for
ME to do is to review data from testing sites. Why? Less bias - not fool-proof - but less bias. Let's face it, if you visit an Avast forum, most will recommend Avast; visit Avira, most will recommend AntiVir; looking for a firewall and visit Check Point, most will recommend ZoneAlarm.
Let me suggest four starting points:
Matousec
http://www.matousec.com/projects/proactive-security-challenge/ is an excellent source of data. Under the heading "Proactive Security Challenge," there are several links to products, testing, and results.
AV-Comparatives
http://www.av-comparatives.org/comparativesreviews/main-tests is another good site. Under the Main Menu, you can select any number of links to the various tests and results in the form of PDF downloads.
AV-Test
http://www.av-test.org/certifications also has PDF DLs of their test results.
Not specifically a testing lab but another good site to visit is Gizzmo's
http://www.techsupportalert.com/ On this home page there are four categories from which you can search. One of these is a wizard which, based on your computing habits, suggests apps that you might consider. It is, of course, just their opinion but you may find it quite helpful.
If it matters, I vary my protection from time-to-time depending on the performance of the current versions of what is available. Currently I use AntiVir, Comodo firewall, WinPatrol, SpywareGuard, Spybot Search & Destroy TeaTimer, and SuperAntiSpyware - all free editions.
Hope this helps. If you have any questions, post back.
Monk