For personal Window users (corporate users have a unique set of rules not worth discussing here) you are a fool to pay money for anti-virus, web security, anti-malware, etc.
For anti-virus, the top free options all perform just as well, and at times better, than paid options. AVG, Avast, and Microsoft Security Essentials are the most recommended. Any of those is fine, I prefer Microsoft's solution as it doesn't require yearly registration and is extremely light in system resources. (It doesn't try to do too much, wasting your computer's memory or constantly annoying you with status reports)
For internet security and anti-malware, you start to run into questions of how much protection do you really need. If you never visit a website of questionable nature and do not blindly click on links sent to you by IM, facebook, etc. you probably can use the above mentioned 3 options.
Internet security and anti-malware are just OK with the free options mentioned. There are better choices, but really if you need more protection than the top anti-virus options provide you are going to get burned anyway and should just invest in an external hard drive and back up your data daily.
If you are determined to pay money for improved security, upgrade to Windows 7. Having Windows 7 plus a free anti-virus solution should be all the protection you need. If you are getting infected with something after that, I am quite confident in saying you probably blindly clicked on something and brought the infection upon yourself. Sometimes tough love is the best love.
AVG is great to have but Norton 360 has never let me down. Best price I got for it was over on 
