Why linux is best

It respects you freedom and privacy.

You can see every line of code it uses, so you can be sure there is no backdoor or keylogger. (The NSA tried 3 times to get a backdoor into linux, but failed)

It runs on older computers, saving them from the landfill.

It is very fast and lightweight.
It cost exactly 0$

Its yours

EVERY SINGLE ASPECT OF LINUX can be modified to however you want, and is only limited by hardware.
It can look real sexy (take a look at r/unixporn).
You don't have a giant, monoply, money-seeking company forcing you to do what it tells you to do, making you the product (im looking at you Microsoft and Apple...)
Many, many options to choose from, to customize it.
You get to brag about how smart you are when a Windoze user sees you "hAcKIng" (I use arch btw).

Its Powerful and secure.

The command line is really good and lets you do very big things in one line.
Package managers make installing software a breeze.
It's almost impossible to get a virus on it, and there are still antiviruses for it.
TONS of support for Linux, ask a question, and in a few minutes people will be responding.
Countless other reasons.