One of the most common elements of children or young adult novels is absent or neglectful parents. This is understandable. Without the presence of strong parental influence, the main characters have the freedom to be the heroes. Everything depends on the kids. It's why the orphan theme is so popular - think Harry Potter, Anne of Green Gables, and more.
Yet I love books with strong families. I particularly love books with a big, loving family full of diverse personalities. When a family is done well, it makes the book stands out.
Twilight comes to my mind first. While I am a fan of Bella and Edward, what really took my feelings for this series from mere like to complete obsession is the Cullens. I love that there is this big family who work together as a team to solve their problems. I love that each character has a distinct personality and history that unfolds throughout the series. (Twilight does have the typical absent parent types in Bella's parents).
More recently, I fell in love with the "family" in Die For Me by Amy Plum. I love the group of revenants who live together as a family. Like the Cullens, they are a big team and have all sorts of different personalities. You have fun-loving Jules and Ambrose, nervous Gaspard, lovable Charlotte, and more. That's not even including Vincent, the handsome love interest. (Full review to come soon)
Other books with strong families that come to mind:
Little Women by Louisa May Alcott
Harry Potter by J.K. Rowling (the Weasleys)
Confessions of the Sullivan Sisters by Natalie Standiford
Piper's Son by Melina Marchetta (actually almost all her books have family elements)
What books can you think of with well-developed family characters?