Statistical Modelling and Model Building

The way you put the lego together, in terms of model building and statistical modelling, will depend on the domain that you're working in as well. And i think this is a wonderful edway into the conversation. So far has been relatively abstract, and i'd like to dive into some particular examples. Because you've seen a plethera of use cases. I'm just wondering what some of the most impactful r telling models, or ones that you've just found interesting, that you've been involved in building.