...Use SP3 or don't use SP3.
But let the "intelligent tech guys" speak for themselves...
(Not saying I am one, but I've read posts here already from some that I know are.)
Coming from a computer technician: WHAT!? You're still using XP? You should switch to Linux or Mac if you want security.
Also, if you choose Mac, always run it in USER-mode when online or you could get that worm that's going around for Macs. The way you do that is to make an account called Administrator that you give all the security privileges to, then turn the administrator privileges off on your user account. That way any time something fishy goes on it will ask you for an administrator's name and password thus offering the same security as most Linux distributions have by default.