This is personal opinion here, but I don't think you need one.
This is why:
Just about every file on your system is owned by root.
As you use your system day-to-day, login as a regular user (not root)
As long as root is the only account that can write to system files, it's virtually impossible to get a virus.
The reason is because any application you run inherits your permissions. That means if you're logged in as "yennon" on your system, any application you run (including any unknown viruses) will not be able to write to the system files. Simply because user "yennon" should not have write access to root's files. The worst that could happen would be personal programs getting infected. Gnome, system tools, and all that should remain clean.
Make sense? If you'd still like one, you can search for one on http://freshmeat.net