X230 Tablet. The stylus works out of the box with Ubuntu 14.04.

Only nit is that the standby battery life is only a few days. I upgraded from the 3-cell (which was pretty old and lasted about two hours) to a 6-cell. I'm still testing it but it lasts at least 5 hours under moderate usage. I think with the brightness on low it could last 10.

I personally ran Ubuntu on the T520P and the T540P over the past 4 years. Both have yet to disappoint me.