I had McAfee for 2 years, but I recently, of last weekend (not this past one) had obtained a trojan and some viruses some way. McAfee was unable to detect the viruses, but got the trojan and 'did not' remove/quarantine it. I used Microsoft's OneCare website to do free scanning, and it removed the trojan, but it also picked up some things that McAfee missed. McAfee was expensive, around $70 a year to use. I uninstalled it and bought OneCare after it removed some of the bugs McAfee didn't pick up, which was $50. I feel that OneCare from Microsoft has been working much better than McAfee. It has tuned up my PC more than McAfee did for some reason.
I had Ad-Aware but had to uninstall it for OneCare, but I still have Spy-bot.












