Drupal 8, What’s not to love?
Fastest Drupal ever, out-of-the-box. Comes with BigPipe, Placeholdering and other crazy stuff, and a better caching system.
New theme system based on Twig. 154 theme functions have been removed and replaced with Twig templates. This is one of the most interesting additions to the theme layer.
Symfony2 as a base layer for Drupal 8. Services, Dependency Injection and Routing are some of the paradigm shifts.
Everything is fieldable, well almost everything. Not only are there new fields, but you can now add fields in many more places.
Drupal 8 ships with CKEditor, one of the very best text editors on the market.
Thanks to the "Quick Edit" module, if you're logged into Drupal and looking at content, you'll be able to edit text directly from the front-end of your site.
Drupal 8 provided image styles but also allows you to choose different styles for individual images. The various styles will be used for different device sizes.
Views is now in the Drupal 8 core. Not only is it available by default, but most of the Drupal administration screens now use Views, which makes them easy to customize.
Drupal 8 is Multi-lingual with with 4 key modules in the core.
With Drupal 8 you'll immediately be able to create a REST quickly out of the box.