The air pump I purchased from Jehmco (DAPMH15, which I think is just a rebranded Alita) gave out this morning after almost 8 years. I haven't opened it up yet to see what failed, but it probably just needs a new diaphragm.
My sump return pump (Laguna Max-Flo 4200) is still going strong after ~8 years.
Eheim Jaeger Heaters (all six of the 300W) appear to still be working great. I know there were some people that were disappointed with the Jaegers after Eheim bought them out and changed them up a bit, but they have been solid for me.
The Ranco controller the Jaegers are hooked up to, also going strong for 8 years.
I run Matala Mat in my sump and the grey high density mat started to really break down after 3 years. The Black low density mat started breaking down after 4 years. By breaking down, I mean that it went noodle soft (lost all rigidity). Both had to be replaced.