Unless you really cannot afford to pay for a PC security suite, I would strongly recommend dropping AVG and Avast. I maintain quite a few computers and used to have either AVG or Avast supported with a mixture of adaware, spybot, etc, for their security setup. Unfortunately over the last year the number of manual cleanups and removals of malware I've had to carry out was becoming ridiculous. I looked into a number of antivirus / spyware test scores and realised AVG & Avast only protect against circa 90% of all known viruses (Letting through ONE in every TEN!?) compared to decent pay-for programs that consistnetly protect against 99.x%
With this knowledge I would now recommend Prevx1, Kaspersky or F-Secure who have all succeeded in keeping my maintenance work down compared to crappy free products.
However, if freebies are your bag, then I guess you're not going to find anything better...