Coney Island is the best for everything - the beach, the rides, the beer - but mostly for the Skee Ball. It's incredibly addicting, affordable and satisfying (depending on your aim).
Arthur Avenue is a mainstay of the Bronx. Since the early 1900's til today, it's been the hub of the Italian-American community that calls the Bronx home. Many family-owned, traditional businesses dot the main avenue, and the food culture is rich and boisterous.
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.