I have a 2012 Retina 15". The first generation. I spec'd it out at the time hoping for it to last me at least a few years.
From 2015 I've been eyeing off every new release of Macbook Pro thinking "yeah this time I'll upgrade" but then I realise there is actually nothing wrong with my current one. Like, nothing at all.
I realise the battery is going die eventually and software updates will no longer be supported at some point, but for now it really is the best computer I've ever owned.
Note: I've been on all sides of the fence (Amiga/win95->winVista/OSX) so I'm not just a fanboi.