I’d suggest Soft Cell, both their old stuff and their new album. The new one, Cruelty Without Beauty (or maybe it’s vice versa, can’t be sure), is probably the best fusion of old synthpop’s sound and technique brought up to date in a clearly identifiable form. Other older bands have updated their equipment but somehow lost “their sound,” but Soft Cell didn’t fall in to that trap.
Heaven 17 was hit or miss in their first era, and then they came out with an album in the late 90’s which, well, was hit or miss. But the hits on Bigger Than America were good enough to merit checking out the disc. Otherwise a greatest hits compilation isn’t a bad buy.
Other artists I’ve mentioned in other threads that fit here are Add N to (X) and VNV Nation. Oh, and for old synthpop the first A Flock of Seagulls album is actually quite good, but some people tell me I’m in a minority thinking that.