Win2k and XP work great for me. I have boxes that have been up for a month or 2 without a problem. Usually only turn them off if theres a storm going thru or I want to replace some hardware.
All the games coming out in the past 2 years or so are fully compatible with win2k/xp. Older games probably wont work, if they were written specifially for 95/98, but most of those would be from the late 90s.
The thing with NT is you need a bigger system to run it well. I'd say at least a 1.5ghz with 512megs ram (get the most ram you can, 2gb isn't enough
. You need at least that much for most games coming out lately. My 1.8ghz game rig is feeling its age (its around 1 year old). Newest games I can't play at full res/quality with a decent framerate.
Drivers arn't a problem. They were a problem with 2k when it first came out, since the NT4 drivers didn't work and the 9x drivers wouldn't work. Some of my equpiment I had to wait a month or so for drivers. But now as long as you don't have a 7 year old isa winmodem or something, drivers arn't an issue.
If you're getting XP, get Pro. The extras are worth it. Oh, and don't get the upgrade if you can afford the full version. just wipe the hdd (backup your configs and such first), and install xp from scratch.
I can give you some pointers on how to setup xp when you're getting ready. The 2k/xp installs are a no brainer. Nothing like the nightmare 9x was (or nt4, if you ever used it. ugh). If you want to call me while your doing it, I can walk you thru the install and the config settings. Or I can call you, doesn't matter.
Friday nights (FSO) at 11 PM Eastern 
