1) Short Term 12
This is one of my favorite movies in recent years, and it really showed what it's like to work in a short term foster home/rehabilitation facility. This film got everything right. It was incredible and Brie Larson is a gem.
2) Running With Scissors
Poor Augusten's mother not only randomly puts him up for adoption when he's a teenager, but she gives him to her odd shrink and his even more bizarre family. Someone is going to be wtf'ing for life.
This cute little indie is about a guy named Brian(Paul Dano) who feels very empty in his life and is trying to adopt a child from China. Then he meets Happy (Zooey Deschanel) and things get a bit weird. It might be the typical "quirky" indie, but I've always liked it.
Bonus: Child of Rage - Sure, this is a Lifetime TV movie but it's based on a true story of a family that adopts a child with severe reactive attachment disorder. It's not a film I'd ever watch again, but I thought of it when I saw this theme. It's intense.