subscription to Trendmicro AV
running 2 gigs of memory on a
I've been using AVG Free for about a year. It seems to do the job as well as the programs that I've bought. It does seem to have some false positives though. Yesterday, it told me of an infected DLL in my roxio directory. Since the file size and date seemed write, I was suspicious. It quarantined the file. I manually updated the the virus definitions, and restored the file from quarantine and it no longer reported a problem. I've seen similar behavior a few other times.
Previously, I've use McAfee, and Nortons. AVG seems to be as good as them, and it is free.
I've received virus infected emails several times. Usually, they are spam from foreign domains. While I've never had an infected machine, I know several people who have had multiple infections. Typically, it was a jpg file from someone that they knew. I don't typically open any attachments unless I am pretty sure I know what it is.