Everyone knew what was going to happen to Walter White from the very 1st episode of Breaking Bad. If he was just going to stop making meth one day and live a normal life, it would have been a stupid story. It was one of the greatest TV series in history BECAUSE people knew he was going to destroy himself and the writers made that path to destruction entertaining.
When I see how TV series did such an awesome job of taking a school teacher to a drug lord over 40 to 50 hours of footage with a TV series budget, I weep at how badly the prequels took a Jedi to a Sith lord in around 7 hours with a top of the line movie budget.
My dream is that one day Vince Gilligan gets the opportunity to tell the story of how Anakin became Darth Vader.