This is a pro tip, but also a summer tip, take the ferry from Lower Manhattan to Rockaway and spent the day. The beach is great and the area is impossible to gasp that it's 30 min from Manhattan (without traffic) - Eat as many tacos you can, cause it's the best in the state of New York!

City Island is a seaside town in the Bronx. Known for its fishing, seafood, and main street it is a self-contained working-class haven. The buildings range from late 1800's houses to 1960's storefronts, and you can smell the ocean everywhere on the island. Restaurants and local pubs dot City Island Ave, and even the few empty storefronts stay vibrant. 

The reputation of Mission Chinese Food is for being cool, weird, and extremely eccentric, which tends to mean that you either love it or hate it (an assessment that is at least somewhat correlated to your personal tolerance for spice).

This is a very delicious Sandwich place in my neighborhood. I normally order the #5 - Bell' americano. It's a great sandwich. Also try the wonderful cookies.

Giant dinosaurs. And the rest of the museum is great if you also like giant whales and outer space and especially the life size dioramas of animals and cave people, which might be the very best Art in all of the city. Sigh.