I used all, and to me

3.x: bad
95: good
98: good
2000: too demanding
XP: good after SP2
Vista: terrible
7: good
8: unbearable

Did you miss the Steam OS announcements? There's definite potential there if Valve can push it appropriately.

I prefer everything over vista, and I think 7 and 8 are the best two os's. Windows 8 really isn't hard to use. The problems people are complaining about are seriously nothing, and are just continually perpetuated by idiots. 

You forgot Windows NT and M.E. (I know, I know. Windows M.E never existed! :P)
Also, Windows 2000 was excellent, it was essentially a Windows 98 skinned version of Windows XP, you could even use device drivers for XP on Windows 2000 and vice versa, problem was it was released at a time where everything was still being built for the 9x platform and not NT, which is the same issue XP had on release, that all got ironed out eventually as focus shifted to development on the NT base.

Vista was also decent after a couple of service packs which bumped up it's performance and compatability, the main issue with Vista' though was it was a big departure from XP and device manufacturers were caught off guard, nVidia was actually responsible for a fraction of the Blue-screens of Death, having OEM's sell PC's with 512Mb of Ram and Vista didn't help matters either, bought a new PC? Stiff. It was going to be slow.

As for Windows 8 specifically, it's downright fantastic on my Phone and Windows Tablet, it just feels right.
However, when thrown on my Eyefinity Desktop PC it was a nightmare, why? Metro just doesn't work over so much screen-real estate, large portions of my screens were just a solid colour with nothing in it, it's downright a waste.

So:
3.x: Good
95: Bad
NT: Good for workstations.
98: Good
2000: Good
M.E: Worse Microsoft OS ever.
XP: Good
Vista: Good after a year+
7: Good
8: Good on select form factors.

I really don't get the hate towards Windows 8. Admittedly when I tried the beta for half a day I thought it was horrible, but decided to give it another, longer try and don't regret it.

I've removed most of what was originally on the start page as I never really used them, I had them customised for other members of the family who aren't that proficient with computers. Right now the start page is filled with games I got from Steam, simply because it looks nice.
I spend most of my time (99.99%) in the desktop "app" and there's no reason for me to ever go back to the metro screen unless I want to look for a program by simply starting to type. All the managing options like Device Manager, Control Panel, Task Manager, Computer Management, etc. are just 2 clicks away in the bottom left corner.
It also comes with built in virtual drives, which was a nice surprise for me.

People who say it is designed solely for tablets obviously haven't extensively worked with the OS. It has everything Windows 7 has and more in regards to the needs of PC owners, it just also happens to have a UI available for touch based interactions. It's only issue is that the platforms that would benefit from this dual-UI functionality aren't very popular.

Excessive much? Sounds like buyer failing to do research first. And failing to do research after purchase, considering there are options to make Windows 8 work just like Windows 7.

But if you were buying a traditional laptop with no touch screen, I'd recommend you stick with Windows 7. Windows 8 works best with touch, just like WIndows Phone 8 and the Xbox One interface (kinect).

No, you cant make W8 work like W7, even with classic shell there are some things missing.

You cant buy high-end laptop with W7 in my country anymore.

Windows 8 is pretty awesome for running on older PCs.

I installed Windows 8 on an older single core netbook and it works great. It ran horrible with XP and Windows 7 but runs great with Windows 8.

I also installed Windows 8 on a Pentium 4 computer and it works great there too.

Less demanding on resources and runs great on old PCs.

So... much better performence is the best thing about it from my experiments.

People who like Windows 8 are __________