Not sure if you're into more avant garde side of synth pop, but Japan's "Tin Drum" is a pinnacle of that sort of thing. "Ghosts", the main single from the record, somehow got to #5 on British charts, which probably makes it the most abrasive and straight-up unconventional pop song to ever hit top 5 in the UK. Overall it's a record to get lost in, very compositionally intricate, detailed and profound. But it's a secondary recommendation. Try Ultravox first wherever you have time.
BTW, these are the only albums of each band I not only like but even care to listen to from start to finish. When John Foxx left Ultravox they immediately degenerated and more early Japan is all aesthetics over content.