Here is a range that is known to work well with Linux:
http://www.lenovo.com/us/en/index.html
Basically all Thinkpads are certified for Linux (Suse and Redhat). Mostly you will have no problems with other distros.
Examples: Thinkpad W510 and Thinkpad L512
In general IBM deserves credit for being Linux compatible.
I also had Mandriva and Arch working on (an older) Toshiba Equium. Worked right out of the box with Mandriva.
What is your experience - I need to know

(And if it is older than 3 years please tell - mainly this should be a list over alternatives that we could buy)