Orange is the New Black
Mindhunter
Stranger Things
House of Cards
Ozark
Aha, Orange is the New Black. I just remember how shocked my mum was when she found me watching it.
But yeah, from what I've seen of the above, I would def say Stranger Things and House of Cards. Maybe Breaking Bad too, since they may be more patient viewers when it comes to TV shows so they may get into and enjoy that.
I would also say Money Heist since my mum loved the shit outta that when I put her on to it.