Had quite a few ThinkPads over the years, and loved most of them.
The T43 was a bit of a donkey, that went in favour of one of my favourites, the T61. My T510 was dropped by it's previous user hard enough to break the plastic fan vent and bend the heatsink fins, and was still working when I was made redundant.
My personal laptop is a T410, I have an X240 from work, and my mum has a T410 I set up for her. I've played with getting a X230 or T420 for myself, but I don't really like 16:9 screens.