This is a question which has been asked by almost everyone but never answered in the true sense because...It DOESNT have an answer! An Operating System is about choice and is often shaped by things such as compatiblity with your hardware.
I have used a variety of operating systems , but I think no Operating System is perfect. Microsoft Windows has its flaws , so do Linux Based Operating Systems. What makes them different (or better) is the degree to which flaws exist. I have decided to Stick with Ubuntu ( its Linux Based and completely Free) , while some others prefer Windows , some even use Macs or other Linux Based Distributions.
You might wanna take a test here , just to find out which Linux Distribution suits your needs best.