The West Wing.
It's on Netflix currently. Lesser-known now, but used to be insanely popular and won a many awards. Besides, if Game of Thrones, Sopranos, and Breaking Bad are "lesser known", then I'm going to pretend The West Wing is lesser known too. Also, The Newsroom is a really good show, and made by Sorkin, who also made The West Wing.
I have a goal to ruin peoples lives by getting them sucked into this show for a few months, one person at a time. Thenewgreen has recently felt the wrath of West Wing time-sink goodness.