Win95, Win98, and the Millennial Edition are all using the same core, so you can lump them together. Windows 2000 and XP use nearly the same kernel, so you an lump them together. Same goes for Windows 3.1 and 3.11. Windows Vista and Windows 7 also use nearly the same kernel. Windows 8 and 10 are hard to say what's changed. I personally haven't used Windows 8, and Windows 10 just works for me. But yes, Microsoft likes to change names of their OS's for marketing. Any new features could have easily been included with an update, as they do now with Windows 10.
For me Vista was the beginning of the end of Windows. They did a lot of things that weren't ready for prime time. Windows 8 was when I really considered using Linux, and Windows 10 pushed me to leave 1 of my PCs to run Windows.