A show that reminds me of "Boardwalk" is "Peaky Blinders", which I'm not sure has ever been discussed here ever. But it's a great show and similarly does an amazing job of evoking the time period (roughly the same one, just across the pond) and is more consistent than "Boardwalk" but arguably hasn't reached the heights of "Boardwalk" at its best. It was apparently David Bowie's TV show, FWIW.
But if you're one of the Babbler's who's never seen "The Wire", that should definitely be your priority. Format doesn't really matter but I recommend watching w/ subtitles because the dialogue is excellent but delivered so naturally it's easy to miss stuff.