In my case i actually moved from Windows and Linux to MacOS. I never thought i would actually like a commercial OS but was proven otherwise. The main reason is to be able to use commercial software and have the flexibility of the bash shell.
I love ArchLinux.
I can learn much more about linux while using Archlinux.
And because of KISS.
Favorite is Ubuntu because i'm working on it for a years <3
Desktop: While I love how elementaryOS and SolusOS looks. My 2 laptops are using Linuxmint (17 & 18) and 1 using Ubuntu 12.04. Definitely using LinuxMint because the easiness, and it is based on Ubuntu (I hate Unity though, so that's why I use LinuxMint).
Server: No favourite. CentOs, Debian, Fedora, Ubuntu, they're just the same for me.
I love Linux. There is no competition against Linux. You can customize everything on it. If you are a programmer you can easily install new packages so you can code.