Dell Precision 5540 with 8-core i9 at 5GHz, 64GB RAM, 512GB SSD and Quadro graphics running Linux.
Currently using its predecessor the Dell Precision 5530 with 6-core i9 at 4.8GHz, 32GB RAM running Kubuntu 19.04 (Fedora was nice too)
I'm over Mac, these new Dell Precision laptops are monsters, they're guaranteed to work with Linux and the experience is nicer than MacOS for dev work.