feh, you should do what I did.
I have win98SE, which I use only to play games. It get's online, but only using Mozilla. Then I have Linux installed on another partition. I use Linux for everything else, I feel safer, it's more stable, and a hell of alot more fun.
Then again, you could get the ultimate upgrade and get a Mac running OSX!
OS X is the best OS in the world IMHO. It can run pretty much all linux applications, UNIX applications, Mac Applications, Windows applications (slowly thrugh an emulator), and it gets native support from many big named Apps. M$ Office (yech!), Adobe, Macromedia, etc.
The Mac is the best platform in the world. There are NO viruses, and the securety is top notch. That is my REAL suggestion, get a Mac
hehhe.... but if you don't. Get Linux at least.