This one is a no-brainer for me. When I was first learning to use computers, you bought mother boards from the back of magazines, and many came with schematics and source code. So, it's only natural that I gravitate towards Linux. Ubuntu is my flavor of choice right now. It's been good enough for me to install on friends computers who aren't all that computer literate. I think that says a lot.
I lean towards KDE, but have had trouble with the latest version. Many of the machines that i have linux on are running Xfce.
What can i say about windows .... Windows was the first GUI OS that I experienced. It's always been buggy. So I started to think that was the norm. In a few cases I have to use windows. Although, these days it's mainly for supporting other windows users. Obviously there are certain programs that only run on windows. So, I'm afraid I'll never be rid of it. It is a necessary evil.
I'm new to this one. So, my opinion isn't completely formed. I find the GUI a bit convoluted. Installers need work, I think.
Let's just list em and link em: