Source
Linux currently 29.1%
Sample size according to StatCounter: 24,353,436 page views
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
Pornhub is legitimately one of the best sites for internet statistics around. It's very widely visited and they actually put out the numbers. (Although, sadly, in my state of Virginia, they comply with identification requirements, so I only visit it with my VPN active, which then fucks up the stats.)
"Best sites"