A few thoughts about endings:
1. I personally love endings that are conclusive and I am pretty sure after reading it that I know what happened. So, yes to Breaking Bad and no to The Soprano's endings. Love the ending of the book, City of Thieves, which was written for adults, but would make a great YA. It ties the ending back to the beginning, and I am a total sucker for that even when I see it coming.
2. When I write, I sometimes know the ending in advance and sometimes don't. Even when I think I know it in advance, sometimes it gets changed up and I have to go with the flow. If I don't know it in advance, I have to trust the process and hope that the characters lead me there. When writers tell other people about characters leading you somewhere, we usually get some pretty weird looks, right?
3. I love ending a book. I mean, I love to finish. I like the process too, but it feels so good to hit send or put that big envelope in the mail. I just finished a six book series for teachers and it was a euphoric moment to see the postal clerk take that last package and toss it in the big outgoing bin.
4. Endings can be gradual, and you are lead there, and the journey is great, you see what's coming, but you can't wait to get there. Abrupt endings are very cool too. I love the element of surprise and the way that ending brings you up short and makes you go back and reconsider everything you read up to that point to see if it makes sense and how you couldn't have seen it coming.
5. My wife loves an epilogue. She wants one for every book and movie. I think that's true for most of us. Once we invest in characters, it is very fun to speculate about what happens to them after this chapter of their lives. There's something really engaging about that. As a writer, sometimes I've had very natural epilogues emerge, but other times I had no real interest in writing about what came next, even though I love all my characters.