I'm still using a circa-2010 Thinkpad W-series (purchased refurbished in 2013). Needs a new cooling module (starting to overheat occasionally), and it's been through a couple battery packs and a keyboard replacement, but those are essentially wear items and it's otherwise still going strong.

So far I've actually stepped right flat on the screen once (it fell out of bed while I was in the bathroom and I couldn't see it under the covers) and I'm going to need to unlearn the habit of picking it up by the screen since other laptops aren't going to tolerate that. The T- and W-series are incredibly, incredibly durable pieces of hardware (note: the new Edge, Yoga, etc series are built much more lightly).

Previously I had a Fujitsu Lifebook T4220 convertible tablet from 2007. That was also very durable. It was built quite lightly but ironically the convertible screen would tend to pivot out of the way when you dropped it, which prevented damage, and since it was so light it tended not to pick up a lot of momentum. One day it just stopped powering up, probably some kind of electrical problem. Happened early 2013, so I got about 5 solid years of daily use from it. I have a broken T4200 I picked up for parts, I've been thinking about trying to troubleshoot it one of these days.

In contrast my fiance had a unibody MacBook Pro (Core2Duo I think, probably circa 2008?) in college and I wasn't nearly as impressed with the design there. The emphasis on passive cooling and having as few fans as possible tended to lead to overheating. What finally killed it was the screen cable going funky (I think). Could probably be replaced, but eh, I'm tired of repasting the damned CPU every 6 months when the overheating dries it out. She has a Thinkpad just like mine now.