So many virus scanners, which one?

[Wada]

I currently use Lavasoft Ad-Aware, Windows Firewall and a Router.

I would like to add a virus scanner for active scans rather than use the online home scan that PC Trend Micro does.

Can someone direct me to which is a solid virus scanner?
I have heard Norton and PC Trend Micro are good. Are they and which one is better? Or are there better ones?

Thanks