OK, dudes, I respect your opinion, but OS for games ? Isn't that weird, I mean you're looking for better OS to play games. Well, first I don't think there is such a thing, because games run the same way all the time independently from OS, the question is if certain OS supports specific game + if it has the best drivers/patches installed (as you couldn't install OpenGL on W2K, to improve gaming quality).
Games are not affected by OS in any other way. It's separate application, that depends on your hardware configuration. All of today's games have lots of special settings, that can improve quality, speed ... The rest is up to HW
It's like these commercials saying some CPU's are better for Internet; cmon get clean & fast connection and smart ISP.
WinXP (& previously WinME) for better gaming, multimedia and internet experience - what a crap >

Just make it not to crash, that's all .
Now about W2K, yep, it loads slower than W98 ( thinking of W2K srv with all the WINS,AD,DNS,DHCP ... it takes 3 mins to start ). But excuse me, W2K is NOS (network OS) and not just OS. Nobody's asking you to reboot every 15 mins, some systems are working around the clock, users just log off. Think of all the network, security, policy, protocols settings. You install more, it loads slowly & slowly. By the way, linux is also loading pretty slow, but boy it works like a charm.
When I installed fresh machines with kick ass configuration, & Intel 10/100 NICs with BIOS, it took ~1.5 minute (!) to load clean W98 only because the damn thing was looking for DHCP server, give it static address and it would save you 40% boot time. Remove the logo, all the DOS crap + startup applications and voila, it takes ~15 sec on average machine to load W98.
For my opinion W98 is best for games because all of games are tested to work properly with W98 and all drivers for common HW. That's all ...
Cheers
Chef