You are the master of machinery. Your are the head hancho on hardware. You are the slickest on software. You are a god among gamers. But the question remains--are you the natural NT user? Think you are? NT and 98se may differ in more ways than you can think!
For starters, lets talk tech. Windows 2000 uses NT5, which, by default, uses the NTFS File Structure, not the FAT16 or FAT32 you are used to! Want to lose some data in the switch? Me neither! Win2k is known for its fabulous stabilty, due to a more stable kernel than Win98, and better error-management programming. This boon is not free. The ability to control, accelerate, and manipulate multimedia is reduced to such an amount that you would think you were using your dad's old 486sx33! Do not use Windows 2000 if you plan on editing video material, running high performance games without the benefit of a top of the line video card, or collect and play an obnoxious amount of MP3's you've downloaded. NT was not made for this. It is a solid operating system designed to maintain stability while serving network customers.
With that said, Windows 98 SE is not perfect either. Want to run an FTP server so your friends can easily get at your impressive collection of MP3's? Do you want to, perchance, run a webpage off your own computer, and become a functional part of the world wide web? If you want to do this with a Windows 98 machine, and still come within 5 feet of it, you are out of luck. Win98 was designed as a comsumer pleaser. It plays games, music, videos, web sites, and images faster than any Windows has before. It is a solid hit with gamers, taking full benefit of DirectX 8 Certified video cards, as well as both Creative and A3D hardware sound acceleration. Want to design images with this OS? Be my guest! Adobe Photoshop alone gives you more than enough power, and now it's optimized for Win98SE. It's not bad for it uses, but Windows 98 is not a server, it's a perfect home computer.
Have we reached a verdict? Sadly, we have not. The choice, unfortunatly, is left to the individual needs of the user. There is no better or worse answer. Consider why you sit in front of your computer, or why you leave it running for weeks on end. This will tell you the wiser path.