Don't know what is the best, but I use Avast Home+Zone Alarm. Recently I removed spyboat, but I'm still secured. I don't know of good spyware but Avast or AVG free should do the Job and Zone alarm and Comodo is a matter of choice.
By the way, did you mean $$$ based too? I will say, Norton is the one to give a go, but be careful on RAM and Speed of your box
for years I haven't used any security tools on my computer, and haven't had any virus related issues. personally, i believe the best protection is being careful what you download, and what websites you visit. even if you have good software, stupidity can still get your computer infested.
What app you use depends on who you are. I like Vipre,anti-virus and anti-spyware in one,doesnt slow you down a bit either. Heres a little advice..I came across McAfee "site advisor" awhile ago and I would feel naked without it.It puts a green,yellow or red emblem next to the site,so you know not to touch it if its red.Best security is to be smart,and site advisor helps you in that field.