I'd normally recommend a ThinkPad, but they've been pretty disappointing lately. Two very recent experiences:

T410s:

* sound doesn't work in latest Ubuntu, need a kernel update for a new PCI ID.

* battery charge percentage goes from 0-10%, where 10% is "full". Apparently the embedded controller decided to change which units it reports current in.

T510:

* black screen when booting Fedora or Ubuntu installers. Caused by lack of drivers for the embedded DisplayPort connection to the LCD panel.

* display backlight brightness controls don't work

* suspend doesn't work, because it has a USB3 controller which fails to suspend, because the upstream kernel doesn't have any suspend/resume support for USB3 controllers yet.

Sigh.