I use the demand (free) versions of all these from time t time, and have read a fair bit of info/reviews/experiences with them. (AVG AS, SAS, and A2). I think that SAS and A2 have the better forum support. A2 has a reputation for more false positives than the others, SAS is probably the best deal, with its pay once/lifetime license.
That said they never find anything on my pc since I started using SpywareTerminator, which you might want to consider.
If not, why not trial each of the other programs, and see which one works best for you. I think they all have good protection and features, and antispyware applications are difficult to test properly for effectiveness, judging by some of the disparities in tests I've seen, so this is probably the best way to go about it.
Does anyone have an opinion on one of these Anti-Spyware's VS the other? I have a great actually FREE A/V, AntiVir from Avira PE Classic, I want to spend some money on an Anti-spyware *IF* need be, what is my best options here? Would A-Squared FREE serve my purposes which I now use? Or should I shell some bucks for a deeper Anti-spyware like AVG(formerly Ewido) or the Super?
Thanks for any direction from the PRO's here,