I personally really like the missions from when they were kids. The bank scene is one of my favorites in season one.
The Eiffel Tower and Lincoln Memorial missions are super cool and even though Ben's ghost (original timeline) has moved on, I'm really curious about what happened to him when they were kids.
And we would get more backstory for the villains living in Hotel Oblivion. (season 4?!?)
(backstory on the Sparrow Academy would also be cool, but its kinda obvious that will be in season three)
I would love to hear some opinions!