The best order to watch this franchise.
These are the anime that have the best openings that I've seen so far. Some of them are so unique and some of them are just the ones you enjoy watching it again and again, even you've already watched it so many times already...
grown-up characters and more complex themes; anime I appreciated as I got older because they had interesting things to say and food for thought, so this list leans towards the serious side, I guess