Just want to toss in that Lenovo likes to cripple certain features in hardware, e.g. limiting SATA II speeds (http://forum.thinkpads.com/viewtopic.php?f=2&t=84953), disabling stereo mix (http://forums.lenovo.com/t5/T400-T500-and-newer-T-series/Is-...) and whitelisting wifi cards (http://www.thinkwiki.org/wiki/Problem_with_unauthorized_Mini...). I think at this point they stopped mucking with SATA, but new models still require "approved" wifi cards and disable stereo mix in hardware.
For those who enjoy the ideas behind Linux, Lenovo is not exactly the greatest manufacturer.
[Edit] And apparently HN does not use Markdown, or I was doing something wrong before.
Just wanted to second this. I've been using Ubuntu on Thinkpads since 2006. It's been 5 years since I really had to deal with the Ye Olde Unix Desktop problems of yore ("why doesn't my wifi / digital camera / suspend resume / etc work").
It's been the same disk image and /home partition this whole time, too -- no full system reinstalls. I just keep upgrading to the oldest supported LTS release, which might have something to do with the fact that everything "just works."
For me, that's Ubuntu on Lenovo hardware. I'm not trying to push this setup, just respond to the idea that 'just works' means you have to use a Mac.