Thinkpads what models are long lasting?

I got a guy from India on the rig wanting a thinkpad. Looking at X60's, X61's, T60, T61, T400's (he wants the smaller around 14" ones). Is there any of those models I should avoid? I have kept up with them some but not enough to know if any of them have had any long term problems. I have never really messed with R series so I don't know if they would be worth getting either.

The motherboards in the R series had a tenancy to well die. I had an R32 around here a while back that wasn't even worth fixing. At work we had a T series doorstop as well. (I think it was a T40 but I dont really recall, That one I am calling user abuse on though, It came back to us completely disgusting) All in all I am very happy with my core 2 duo x60. I did tare the entire lcd panel assembly apart to replace a bad backlight although to be fair the previous owner probably figured out a way to break the first one. All in all it has been a very reliable laptop. It would be awesome if I maxed its ram and put an ssd in it. I even got the dock for it off of ebay for $20. The guy listed it as having a dvd/cd-rw combo drive and when I got it it had a dvd+/-rw multi in it that works great. Which is awesome because at the time that drive was selling on ebay for a strong $50-80.

Have you checked out the advanced dock for them? You can put a desktop video card in them and use that on an external monitor.

I had a T400 for work and it was dodgy. I had screen problems, wireless connectivity problems, keyboard problems, and the case started cracking after light use (and I tend to baby my gear). Not sure I'd touch another.