Dell recently added more Linux goodness to their line of laptops . . . All support Ubuntu LTS (Long Term Support) versions of Ubuntu from 16.04 (aka Xenial Xerus) to 18.04 (aka Bionic Beaver).
Note that “the Beaver” runs Gnome3 versus “Xenial” which runs the classic Unity desktop. Dell will ship with your choice.
For reference, pls see screenshots (3) below:
Below are two slightly customized Ubuntu desktops w/Unity classic DE . .
Below is the new Gnome3 Shell desktop . . showing the apps view screen . . this is the standard desktop now on Ubuntu 18.04 (the latest release) . .