Update 2023/03/02: Using Pop!_OS 22.04 LTS. Just install and enjoy, not much to say about, it just works.
Update 2020/05/19: I'm using PopOS 20.04. Works great!!
NOTE: At the moment Dell G3 series doesn't officially support Ubuntu 18.04.
This post on Reddit: https://www.reddit.com/r/Ubuntu/comments/b74vvb/ubuntu_1604_on_dell_g3/