First thing to do:
Get the live bootable DVD installer of gentoo linux (no meme plx) so you'll be able to try out ALL the different desktop environments.
DEs or desktop environments target different users.
Descending order of bloat:
KDE Plasma for people who love to customize almost anything incl animations and you can even rotate widgets! (how cool is that eh?) Comes with a nice GUI but beware of crashes! Works best with a bleeding edge (or up to date) distros and the best choice for this would be OpenSUSE tumbleweed420.
memory hog and CPU hog. low-end devices such as netbooks are it's nemesis! 2GHz 2008 dualcore processors and a 2GB ram would do fine otherwise it'll be unusable.
Unity is just simple. For those who hate GNOME. Unity is recommended for first timers. Ubuntu is the distro! Stable and smooth.
GNOME is like KDE but less tweakable, less settings than KDE, OK tier. much more memory hog than KDE Plasma (Last I checked!) but less CPU hog! Stutters sometimes.
Cinnamon for those who like Windows. Linux Mint is the way but why choose the kike distro with a horrible logo? You can get fedora spins or opensuse version with cinnamon preinstalled.
Openbox, XFCE, i3 , iceWM are for those who like it minimal, those who don't compromise performance with graphical fancies. It doesn't require you to use bleeding edge distros! low-end devices are its friend! 1GB
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Which DE?
Minimal net install or fully packaged distro?
Bleeding Edge Stable or Unstable or Stable distro?
Package manager?
Which *nix file system?
For me Arch, Debian, Gentoo/Funtoo, Mageia, Fedora, OpenSUSE, Ubuntu are the best choice.
I personally don't recommend manjaro and mint. Mint is kike. Manjaro is 'oh look we surpassed arch's packages version we a better rolling release now' then suddenly whole system crashes, everything's gone.
Pick your distro wisely or you'll end up doing another full new install just because 'x' and 'y' program can't be installed due to lazy distro devs who don't update core dependencies (such as Xorg). Choose the distro that won't die after a few years because making another setup and migration is a complete pain. Pick those that'd been well maintained by an awesome team of devs and maintainers, those who patch security fast and comes with a complete wiki and documentation. Manjaro and mint is known to lazily release security patches although the 'large userbase' is just the result of "justwerks" syndrome. It's not really bad since it is the gateway for spawns. Also pick ones that can be trusted, you don't want your /home/ folder and torrents gone just because of a filesystem bug right?
Don't forget about the BSD distros, they're awesome too!