What antivirus program is the best for a computer?

I know that Norton might rock, but myself personally, I can't tolerate the way it uses all of my ram and slows my computer down. I use spy bot, but that isn't enough. Is there anyone out there who knows of an antivirus program that will not eat up my bank account or my computer's capacity to function at a normal rate? Thank you for your time......

Originally Posted by mONOSEQ

I know that Norton might rock, but myself personally, I can't tolerate the way it uses all of my ram and slows my computer down. I use spy bot, but that isn't enough. Is there anyone out there who knows of an antivirus program that will not eat up my bank account or my computer's capacity to function at a normal rate? Thank you for your time......

Free - Avast
Commercial - Kaspersky