"It just works"
..because that is the state of a mainstream modern distro, and it's not true of Windows anymore.
Alternatively "No nagging, no forced online account."
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
"It just works"
..because that is the state of a mainstream modern distro, and it's not true of Windows anymore.
Alternatively "No nagging, no forced online account."
Two out of 10 Linux users agree that insert name here
is the best distro
"We hope you like config files"
"Own your computer" and "Free your computer"
"It does exactly what you tell it to do."
Own your Computer
Hurts So Good
*Hurds
The least annoying launcher for your web browser
With a bit of a double-entendre, "It powers the world", since it's the most common server platform.
More funny: "It's not an OS. It's a hobby."
Batman runs Linux. Shouldn't you?
Buy it, own it.
Sovereign Computing
“If you knew what it was, you’d be using it already.”
Wobbly Windows in a Windows-less World
Forget the hardware
YOU deserve better
Build a Legacy, not a Lock-In
Think ~~Different~~ Freely.
If you don't read the man pages, we're going to ban you from the chat.
lol I was going to suggest "it just works"
I would not have suggested that before this year but it's definitely true now, or at least truer than for Windows/Apple.
Tailored for You, By You
I'd copy you and drop the hardware. Just: you deserve better
RTFW
Probably thing valve does where all the other players in the market are so shit, you doing very little garners huge public support.
Jokingly: "Linux is free if your time is worthless"
Though this tongue-in-cheek tagline takes the "free as in free beer" misinterpretation of the term "free software", I've always found it a fun way to describe the time investment you'll need to make if you've spent your whole life using Windows before making the switch.
You can fix it, really. :)
"Linux...
"Because you don't have to be the product"
"No overlords"
"What spying?"
"Infinitely extendable"
Which one do you like best?