I'm using the Zone Alarm Security Suite...The Antivirus has worked very good for me..It even has a special Byte-Level scan that well..it scans every little byte on ur computer basically ..idk its like a really thourough scan that should only be used if you got a bad virus cuz it took me a wicked long time to finish..I just left it there before I went to sleep for it to finish.. and I trusted the Firewall for the past 3 years.. so basically, go with ZA if its cheaper IMO
i used to have avast but i got rid of it, im gonna try norton or mcafee, but u could go with sygate firewall but that made my computer very slow but u may like it, ive heard really good things about it