I use and support Free and Open Source Software (FOSS). Open source software is safer, as the source code of it is open for review by anyone. On the other hand closed source software made by the big corps (crApple, Micro$oft, bAdobe) cannot be comprehensively reviewed (as the source code is proprietary and secret) and hence it gives the user little to no control. Micro$ost Windoze 7/8/10 is known to scan ALL user data, including and not limited to contacts, calendar entries, contents of emails, and sends it to Micro$oft for who knows what (analysing, selling or otherwise monetising or exploiting). If you do not like this you should use a Linux based operating system.
Linux (the kernel) is maintained by zillions of volunteers and some paid professionals, even Micro$oft is contributing to its development. On top of the kernel there are tools for file-related operations, user management and software package management and a user interface (such as Cinnamon, KDE, Gnome etc). All these together form a Linux distribution. By the way long before crApple and Groogle had there app stores to centrally manage software and updates Linux was using “software repositories” for the same purpose.
Luckily as Linux distributions are open source there is far less chance of someone slipping something nasty in it, such as the Windoze spydates. Linux distributions get security updates as soon as those are released, unlike Micro$oft Windoze, where you get once a month updates mixed with whatever Micro$oft feels like forcing onto their unfortunate users.
Were these reasons enough for you to want to check out Linux? If so there is a FREE (as in free beer) comprehensive online course being offered by the Linux Foundation “Introduction to Linux”
Linux Mint: beginner-friendly (for people upgrading from Windoze)
Debian: one of the oldest and best distributions. For advanced users
Trisquel GNU/Linux: a distribution which only contains free and open source software, endorsed by the Free Software Foundation
The DistroWatch website has a list of the 100 (!) most popular Linux distributions and news about them.
LibreOffice: does almost everything as other office suites
VLC Media Player: plays (almost) every video/audio file on this planet
Pale Moon: based on Firefox without the Digital Restriction Management
If you need more free and open source software check out the Free Software Directory, which contains over 15,000 free software packages.