Joseph Leonard is one of my favorite cozy spots for brunch on the weekend. After a long week of work their avocado toast and a bloody mary hits the spot. Get there early or expect to wait, it's small and limited seating. Their sister restaurant Jeffreys Grocery across the street is also very good, but no expresso drinks which and I need my morning latte.
Grand Central is big and beautiful and it also periodically hosts free cultural events - poets at typewriters custom-composing poems on demand - or Alvin Ailey dancers performing in Artist, Nick Cave's horse suits!
I think it takes place every Saturday morning to afternoon, vintage shopping while having a great view at the Manhattan skyline from the East River State park. You will find lots of vintage shops and warehouses around this area of Williamsburg.