Which operating system do you prefer?

[Tiberius]

Beauty is in the eye of the beholder.

It's best not to argue over it, for I know I'm right and you know you're right.

There's not really any "right" way of thinking when it comes to operating systems. They all have a purpose, and depending on the way you rank them, a different operating system will come out on top each time.

As for the flawless part... well... windows 7 works much better than any previous version of windows... And can run for days without any problem... just like a linux machine.
Then come the updates requiring a reboot

The "working much better than previous versions" rule applies to pretty much all of Microsoft products though, and most products in general. There are of course exceptions, but generally speaking functionality improves with each version number.

I'm also aware it can run for days without problems. My point was, can it run for years (as servers have to) without problems of having to restart services / the entire OS at multiple points. My experience would be that it cannot, or at least that when compared to Linux based servers, the downtime is far less with Linux.

So I voted for XP. It is the last OS from Microsoft where I have full CDs are available for re-installs.  It is where I got off the treadmill and I don't stay current.

That's just incorrect. When my company bought a copy of Windows 7 a few years back we got a CD with the OS on it. Are you talking about buying a computer from scratch and receiving the OS install CD, because that's not the fault of Microsoft, that's generally the decision of the computer manufacturer (e.g. Dell).

I have XP on half a dozen machines on my home network and have never paid more than $30 for a desktop with OS or $40 for a laptop. 

If you are still running XP then you are really asking for trouble. Microsoft aren't releasing updates for XP anymore, and that's been the case for over a year now.

I sit in front of my computer virtually every minute I'm home and I don't recall a single hickup with the OS in the 6 years I've been running it.

Then you either have bad recall or are one of the exceptionally lucky few.