Ultravox

Ultravox never really found consistent success in the US, but did quite well in the UK and Europe.  They have elements that fit into post-punk, new wave, and prog rock, which you might think would mean they would have garnered a sizeable crowd, but those fickle Americans just wanted them to tick 1 box.  Their early years were fronted by John Foxx, then by Midge Ure in the '80s, both of whom went on to their own modestly successful solo careers.  Definitely an underrated band considering their longevity.