You can choose the order of your Activity Types, ensuring that the most important or most used are near the top of the list.
To set the order of Activity Types, go to Tools & Settings > Customization > Display Settings > Activity Types
Here you can add, edit and remove custom Activity Types (only custom types are editable) and use the drag-handle to change the order that they appear:
This will be reflected in the Action Menus and Create Activity option menus:
