Generations is the EP I was the most excited for when it first came out because my favourite part of the game is family building!! I agree on both of those points though, those two things are very annoying, and I hate the autonomous pranks for kids and teens too.
In terms of which EP to get next, there's not much I can say that someone hasn't already put out there. I find that Seasons most seamlessly integrates into every game file without a lot of effort. Ambitions adds a lot of good features and is easy to pick up as well! University is one I was really excited for but I've only used the core draw of the game a few times. It's something where it needs to be your deliberate goal to use it, especially with the cost of university and having to save up for it.