Normally I'd have the same opinion about most laptops being shoddy built with a missing wifi or audio driver for linux here and there, but I've been playing around with the 14" HP Probook from 2012 I think? I haven't had much trouble running ubuntu on it and I'm very impressed with the build quality. Second hand, sandybridge i5 with some extra RAM thrown in, couldn't be happier :)
I should also note that I'm by no means a power user, I'm still learning the ropes on Linux but I'm pretty fed up with Windows so I figure now is as good a time as any to make the transition!
EDIT: It also occurred to me that you were probably talking about more current laptops, in which case I can't really help you, but apparently neither can apple so I guess we wait :(