I have SAS on demand and ST both on demand and real time protection like many of you are recommending in the AVAST FORUM. I also have A2 on demand. When it updates each days, it shows a update for thousands of spywares and worms etc… while SAS updates now & then for about 50 new kinds of a certain category of Trojan. Why is SAS better now? Also, nobody ever seems to talk about Tenebril’s free SpyCatcher Express antispyware software (both on demand and real time protection). I personnally stopped using it when it was detected as malware(FP?) by one of my security software I don’t remember exactly which one (ST). Still, it was detecting a lot of malwares but there was a lot of FP there. :-\
A-Squared & Ad-Aware have lots of fp’s, on my machines all they found was fp’s. Dumped 'em.
I personally never tried SpyCatcher, but all reviews I’ve read say it wasn’t good. Being as the antispyware that I use does an excellent job, I didn’t bother to try SpyCatcher for my self.
Oh yeah!!! I remember now. It was AVG antirootkit that recognized last year one of SpyCatcher’s component as a “rootkit”. They too have FP, that’s the world we’re in!!! 
AVG ARKT has got FP too.
I think Spycatcher isn’t very good, but not because ia rogue program, simply hasn’t got a good detection.
Believe it or not a few years ago Superantispyware was on the rogue list… But they then got their act together and in my opinion are now one of the best Antispies on the market. OK so the free version does not have resident protection… but on their latest version (4.0.112.0) they now have a right click scan function.
AdAware and Spybot are now struggling to keep level and are not even catching up…
As for the others I have not yet tried them, although from the results I have seen on Geeks to Go with AVG ( where I moderate in the malware forum ) the results are somewhat less than inspiring.
Just my 2 pennorth 