A Single Bead, by Stephanie Engelman, is not only well written: it tells a good story and taps into the heart of the reader.
It's good fiction that has Catholic themes. If you're not Catholic, you'll still enjoy it. If you are Catholic, you'll "get" it.
The storyline explores death and prayer, but in a completely natural way. It also considers how adults don't have it all together, how families, though imperfect, can pull together through hardship, and ways to pray and not be a total dork about it.
This book, while being unabashedly Catholic and Christian, is not unabashedly boring. It explores grief and depression and faces the burden of both. It's also a perspective that feels very real: the teens in this book aren't goody-two-shoes who pray all day, and there's even a scene where there's a "speed rosary" prayed. (That made me laugh.)
The characters have their flaws and foibles, just like real people. As someone who's been hanging around teens for the last few years (though not living with them, tis true), it struck me as very spot on.