Dell currently makes two laptops that officially support Ubuntu and they're great. I had my company buy me one when I started there and I'm very happy with it.
System76. I use a System76 laptop right now.
They are nice laptops but unfortunately not a viable option if you don't live in the US.
Yeah they're not bad, I have had one of their products for almost 5 years now and it works pretty well. I wish they had a 13'' in their line of product though.
Well I'll give them that the options are awesome, 64 GB of Ram and PCIe solid state drives with top of the line graphics and CPU for about the same as a top of the line MacBook Pro $3+k. But it is heavy, kind of ugly, and low battery life. Which to me means I might as well just buy a desktop for less.