Well, anything by them but specifically the Model 500 telephone set.
63 years old and still works just like it came out of the factory. The only maintenance is a bit of cleaning with soapy water and tapping the microphone against something hard every few years to pack the carbon granules.
Also remarkable is that it will still work on just about any phone system in the world. That's a long lasting communication standard.
Another great line of products were pre-1990 Motorola two way radios. They were build almost as well as the WE stuff.