I have to admit, after much reading across the YA genre, I think the books that deal with the rough issues- the dark, edgy, raw and emotional ones- are the ones I prefer. If I had to only choose one subsection and never go out of it, this would be it. The reason? When done well, it makes me feel something. It grips me, tugs me in a ton of directions and mostly importantly, throws me into someone else's position and changes the way I think about things. There are two authors who immediately spring to mind when I think of these kind of books- the ones that take a hard situation, put someone in it, and it's the reader that comes out changed. This is an incredibly hard skill to master and a likely harder mindset to get into for the actual writing process.
Being appreciated today is Laura Wiess, author of Such A Pretty Girl, Leftovers, and How It Ends, and Courtney Summers, author of Cracked Up To Be and Some Girls Are. Both women know how to write characters you just might want to hate but in the end, you side with them and that is a fantastic feat. The books mentioned above are the kind that stay with you, that you use to compare other books to, that set a certain standard. While it may be their books that are brought up, it's their work regardless.
You can find Laura on her website and Courtney on her website and on twitter.