What makes a good book?

I read Best Friends for Frances to Laurel tonight before bed. It's a longish picture book about neighborhood kids fighting and making up. And going on adventures with wildly indulgent picnic lunches. I loved this book when I was a kid, and Laurel has picked it three nights in a row, so I think it's growing on her, too. This afternoon, when we were reading it, yet again, I realized that what I love about this whole series is that the kids (badgers?) work out their own problems. They get in fights, and say mean things to each other, and there's lots of crying. But in the end, they figure out some way to make it work. What books did you love as a kid? What were the books that your kids pick out over and over again, but you hate?