For me it’s Kaspersky Internet Security (KIS) 2009 8.0.0.454

But these are also very good>
Bitdefender
NOD32
AVIRA
AVAST
Spyware Doctor Internet Security
Trend Micro Internet Security pro
F-secure
Norton Internet Security

I think AVG is one of the best around. I’ve tried several over the years and Norton, McAfee and the like tend to be resource hogs. I don’t think they are really any better. What ever you do just make sure you pick one and stay with it. Having downloaded and removed one to try another will really scramble your computers brain. If you are using Vista be sure to go to the prefetch file and delete any other virus software files. good luck and have a great day. Go to pctools.com and download Threatfire to run in conjunction with your other security programs in that it will work smoothly with them. good luck and have a great day

I too have been down the road on protection software. After all of it I have gone back to Norton.

If you want to spend cash, Kaspersky is a russian made anti-spyware, active scanner and anti-virus. It can control every single byte that exits or enters your computer if you set it up right. I believe it also comes with an anti-rootkit (registry invasions)
roughly $70-$80 per year (if i remember correctly)

For free
AVG anti-virus
Comodo Firewall
ZoneAlarm firewall
Adaware 2008 (anti-spyware)
Avast Anti-Virus

any one of these are very good programs, and ive used every one personally