From Kraftwerk's golden era, Computer World has aged the least well. I still like it, but I recognize that it's mostly chintzy; seriously, "Pocket Calculator," as fun as it is, is very much an artifact of its time. (Also, "Numbers" was an obv. influence on DJ Shadow's "The Number Song." C'mon.)
Their other stuff has fared better over the years, though. Sure, the sounds you hear on Trans Europe Express or The Man Machine may've not been produced by a laptop, but Ralf and Florian's songwriting was top notch. The alone is enough to make up for the primitive instrumentation.