I'd be a rich man, if I was given a nickel every time I hear someone say that they don't make movies for adults anymore. How about trying some of these new crime films, like Prisoners or Mud or A Most Violent Year?
The last one, directed by J.C. Chandor, is a very serious film taking place in 1981, with Oscar Isaac playing a business man trying to make it big and keeping it honest, even though he's married to a mob princess. The police are interested in what he's doing, and someone is hijacking his gas trucks. There's only little violence, only one car chase, but plenty of tension and threat hovering over our hero - who's not a hero in the least, but he's no scumbag either. There's lots of interesting ambivalence in the people of the film, and in the end we are not wiser. There's a clever twist in the end, which you may or may not notice.
Chandor writes and directs with ease and sureness, which makes me want to check out his earlier films, All Is Lost (with no other actors than Robert Redford) and Margin Call.