I use XP 7 years already, I do not updates... well, upgrade to service pack 3 only, one time.
I do not install antivirus... well, I have USB Disk Security which handle plugged in USB, but it doesn't count as antivirus.
I know how to take care my PC. If you don't know how to take care your PC, you better go buy windows 7, 8, 8.1, etc. Because they provide upgrade and make you feels more safer.
If I got to moved from windows XP to 7, it's when most of my used program can't work normally again in windows XP. Actually, there's one thing I'm afraid of, and that's not hacker, nor virus, but google chrome browser updates when it doesn't compatible anymore with XP.