If you're far up in Greenpoint and need caffeine + snack, Bakeri is my spot (I say "bake-ery", others say "bach-ery"—I still vote the former). Known for their baked goods—both savory and sweet—it's the perfect spot for a coffee meeting, small breakfast, or a solo book read. There's one large communal table in the center, plus a few two-tops and decent counter space—one of the rare cafes with enough room that it's rarely packed (except saturday!).
Daytime café, nighttime bar. Nothing stronger than 30-proof. Delicious beer and really good wine. Kind people run & staff the place. The garden in the Summer is perfect. I make near-daily visits.
You can't say you've seen NYC until you've seen it from a boat. Hop on the ferry from anywhere to anywhere and you'll see what I mean. Not only will you see excellent old buildings and factories--the inner workings of the old industrial city--but you'll head out under working bridges and see the skyscrapers in all their towering glory. And once you've done it, do it again, at night.
On the west side highway...I don't ride much anymore but I stlll love hanging there, meet people, take pictures, look at the new school and old pros (It's Steve Olson on the pix) also one of the top spot to look at the sun come down...