I would actually consider dense urban cul-de-sacs (or just quieter streets with less road noise in general) for knowing neighbors well. My issue with grids is there's generally an arterial street where apartments are crammed and nobody knows each other due to road noise.
References:
- sebastian hunger anecdote on cul de sacs: https://youtu.be/E9K43cXZg2Q?si=4Z5WgE4izKM5A0SF
- don appleyard's livable streets: https://vimeo.com/16399180
Can't find it but recall seeing a map someone made of a city in southeast Asia (Thailand or vietnam) illustrating how theres lots of cul-de-sacs