Best Windows Operating Systems to use?

Hello everyone,

I'm wondering what is your guys best Windows Operating Systems and why is the best one?

You can vote by the poll and explain why it's the best one to use out of all of them in total. I am ONLY going from Windows XP in the poll.

I'm using: Windows 7 Ultimate and I think it's the best Windows Operating System to use. Better then Windows 10 tho...