Any X or T series with intel video tends to work pretty well. I've personally had great results with Ubuntu on a T410, T420, T520, T530, X1, X60 in the last few years.
This comment was typed on my own 4-year-old x201 :)
(Running Mint 17.1, which broke the display popup for brightness, but curiously not for audio.)
Anyway, if you're going to mod laptops to say that they're good, then many laptops will re-enter the fray :)