Below you will find a list of links to vendors to purchase Ubuntu machines.
Link Status: http://www.dell.com/developers good link to easily find machines with Ubuntu available
Warning many of these machines default to Windows, please make sure to choose Ubuntu in the OS menu.
Ubuntu Version: Ubuntu 14.04
Certification Status: (This field is a work in progress) Canonical Official.
Precision Workstations Starting at $629
Link Status: https://system76.com/ Great link because they exclusively sell Ubuntu machines!
Ubuntu Version: Ubuntu 16.04 LTS
Certification Status: (This field is a work in progress)
Entroware - Entroware is the UK's best dedicated supplier of Linux powered Desktops and Laptops.
Efficient PC - Sell Ubuntu Linux Laptops, Desktops, Gaming and Mythtv systems in the UK and Europe.
The Linux Emporium - Sell many Linux and open source related products as well as providing consulting services and training, especially Python training. We sell not only software, but also hardware - Linux laptops prebuilt with Linux.
Axiomtech - Sell pre-installed Ubuntu machines and services.
Ekimia - A complete line of laptops and desktops preinstalled With Ubuntu GNU/Linux shipping from France to all over the world.