Look for Kaspersky, which is pretty good. If your work uses Sophos, their support contract actually allows you to use the 'standalone' version on your home PC. IMO, Sophos is the danglies - it doesn't cripple the machine, but still manages to do a pretty decent job of it.

Avoid McAfee like the plague - it couldn't detect a cold, and will cripple your machine while it's busy being crap. Symantec's AV is very good at detection, but in my experience, like McAfee it suffers from being bloated, and cripples the machine.

Just my 10p.