Kapersky's the official one at work - I imagine it's been tested for things like detection rates and analysis against the others as the guy who selected it is very, very thorough. I found it to be a bit heavy though, and slowed things down too much.
The only ones of the free ones that didn't piss me off with yearly registering and were sufficently light were Avira AntiVir, Avast (with animated system tray items off) and AVG.
AntiVir used to have the occasional spack and not autoupdate, Avast couldn't cope with all the connections NZB-O-Matic opened, and AVG tends to be a bit slow at recognising new threats - it detects stuff that's on a disk, that it shouldn't have allowed there in the first place, breaks games sometimes with false positives and doesn't play nice with other products.
Despite this, I use AVG for resident, but do web-based scans as well as the ones on the
Windows Ultimate Boot CD periodically, rather than trust a single product.
Oddly I've never considered paying for one, if I did it would probably be NOD32, but I never get around to trialling it.
for simiantec is needed. You got a good sauce berk?
