Lenovo G series. i5-3230M + 8GB. No extra graphics. Bought it without any OS. Installed Ubuntu 13.04, everything worked without tweaking, including the Skype client for Linux. Great value for money.
I use it plugged into an external screen/keyboard most of the time but I do work on it directly when traveling.
I've got a larger thinkpad with 2x the cores/ram and I rarely use it. The light factor is compelling for me.