What are your favorite Linux distros?
Post your favorite Linux distros for the specified purpose, and give a brief reason why. I'll start.
Ubuntu / Kubuntu / Lubuntu - General use, good for pretty much all purposes, Windows alternative. The easiest to use, most developed desktop distro. Everything just works, very graphical, mouse clicks can accomplish everything just like in Windows. No need for command prompt usage unless doing something very advanced. Kubuntu has a Windows-like desktop environment, Lubuntu has LXDE which is a lightweight desktop environment. My favorite version of this distro is Ubuntu Budgie, which uses a GTK 3 based desktop environment.
Tails - Debian based distro for privacy and limited general use, or bypassing network restrictions (e.g. if you want to browse restricted sites, so this is a must-have at school). All network traffic is routed through the Tor network. Comes with Tor Browser and Tor enabled Thunderbird. Tails is meant to be run live (off of a USB stick, not permanently installed) hence the emphasis on privacy anywhere you go. Comes with basic applications like an equivalent to MS Office, GIMP and other graphics editing, Audacity, so it is good for general use but you are not meant to install other software on it. You can enable persistent storage on Tails, which is encrypted when not in use.
Parrot - Security and privacy distro, but also a lite one for normal use (not worth using over Ubuntu or Mint at present, very limited application support in comparison though you can try adding Ubuntu repos and hope for the best). Debian based and pulls from Kali Linux repos, includes just about everything Kali has and more (the only exception I've found is Sparta which installed no problem). Way more capable than Kali, which is a much bigger pain in the ass. Comes with Libre office suite, general programs for graphics, programming tools including Atom. Both Firefox and Tor preinstalled for internet with uBlock Origin, Claws Mail email client, everything you'd need for general use and security testing. For privacy, it can route all traffic over both Tor and I2P! I say don't bother with Kali at this point, use this instead, but again it is no replacement for Ubuntu.
Puppy - For underpowered and old machines that need the least resource intensive OS there is, and for general use on said machines.
openSUSE - General purpose rpm distro with two versions; one with long term support, and a rolling release model. Uses KDE by default but also offers Gnome 3 and non-graphical installations, and you can install all supported desktop environments at once and it won't have a problem with it. Known for being incredibly robust even by Linux standards, with the best and most powerful system tools of any operating system (YaST 2). More specifically, the best tools for managing, maintaining, and configuring the system, from its networking settings to hardware level settings (its partitioner is to die for) to software (package) management, these tools are the most powerful and useful yet also the most streamlined even compared to Windows. Really the best fundamental platform for a desktop OS and a damn good server one too (I'd use this over CentOS/RHEL more often than not, less chance of breaking installations or worse), it just lacks the application support that Ubuntu has. Therefore, openSUSE is most recommended for developers and also for simpler non-critical server applications. Keep an eye on this distro, since all it needs is software support to compete with the likes of Ubuntu.
SteamOS - Gaming, especially for console gamers who need a console-like interface.