The ability to create a custom object, with a custom name, similar to (People), and have this object associated to a person or any other record.
For example, this object could be deals. And the ability to create a deal and associate this as a one to many would be nice.
This could then appear as an additional menu item on the left hand side with it's own respective fields. Here's an example of how Hubspot are doing this: https://knowledge.hubspot.com/crm-setup/use-custom-objects