I'm beginning to come around to the same thoughts. I've used Norton for years, still using it on my main computer, and haven't had too much trouble. But it does ignore some things. That's why I also use Spybot S&D (free) and a new one, for me, MalwareBytes (also free). I've found that nothing really catches everything, but using multiple programs can pretty much eliminate the vast majority. And I'm using AVG (free) on my two older machines, which are really not used too much. I'm experimenting with them, though, and AVG, in combination with Spybot's Tea Timer, has caught some problems before they could install themselves on my machine.
I used to use Ad-Aware, too, but I don't much care for their latest revisions, so I've stopped using it.