Distros
This is a distribution, or a specific configuration on top of the base GNU/Linux system. See here for more detail.
See DistroWatch for a full list of Linux Distributions.
Beginner
Mint
Parent Distro: Ubuntu
Pros:
- Built on Ubuntu
Cons:
- None
Ubuntu
Parent Distro: Debian
Pros:
- This is the most common user friendly choice for computers
Cons:
- Uses snaps for some applications, which take up more space and may startup slower than a non-snap version
Manjaro
Parent Distro: Arch
Pros:
- 
Accessible to both newcomers and has extensive options for more experienced users 
- 
Easier to install than Arch 
- 
Built on Arch 
Cons:
- Not as user friendly as Ubuntu
Pop OS
Parent Distro: Ubuntu
Pros:
- 
Gaming 
- 
Made by system76 
Cons:
- Only has support for one desktop environment
Intermediate
OpenSUSE
Parent Distro: Independent Pros:
- Some rare pieces of scientific software will focus on supporting openSUSE
Cons:
- 
Few people use comparatively 
- 
Lack of Pros 
Debian
Parent Distro: Independent Pros:
- 
Less bloat that would normally come with Ubuntu 
- 
Works on a Raspberry Pi 
Cons:
- Lack of Pros
Fedora
Parent Distro: Independent Pros:
- Less bloat
Cons:
- 
Lack of Pros 
- 
Less user friendly 
Advanced
CentOS
This is normally a server OS, yet it can also be used as a normal operating system as well. Parent Distro: Fedora Pros:
- 
Made for servers 
- 
Stability 
Cons:
- 
Less user friendly 
- 
Older software (takes time to get feature updates) 
Arch
Parent Distro: Independent Pros:
- 
Just what you need to run a system 
- 
Practically no bloat 
- 
Small 
- 
Newest software 
Cons:
- 
Less user friendly 
- 
Can be pain to install, as you do everything manually 
- 
Manjaro is easier to install 
Crazy
Qubes OS
Parent Distro: Fedora
Everything in this distro runs in VMs, so you can run Fedora/Debian/Arch applications nearly seamlessly. Pros:
- 
Security 
- 
Custom-ability 
- 
Multiple distros simultaneously, so you can handpick the distro for the job 
Cons:
- 
Can just break 
- 
Smaller project 
- 
Less support 
- 
Takes time and knowledge of how the VMs are arranged to setup properly 
- 
Does not run in a VM 
- 
Requires your CPU to have certain technologies 
- 
Takes a Lot of RAM 
Gentoo
You have to compile this yourself. Parent Distro: Independent Pros:
- 
Just what you need to run a system 
- 
Practically no bloat 
- 
Can run on strange architectures 
- 
Can be installed beside Android 
Cons:
- Is a pain to install