Someone on another thread mentioned The Sea Devils as an obscure DC property that they like. Got me thinking about how TSDs were really creatures of their time, Challengers of the Unknown knockoffs that came along during an early 1960s fascination with scuba-diving.
I don't know if you could ever make them really fly (or swim) again in today's world.
What are some others DCs done that are just hopelessly products of their time?