I love that there's a museum dedicated to American art, founded at a time when American artists were underappreciated. The exhibitions are curated with a broad but discerning eye, and the architecture is spectacular. In my experience it's typically much quieter than the obvious choices like the Met and the MoMA - although both are remarkable, there's something I love about the scale and style of the Whitney.
This is a hot spot for plant enthusiasts. A recurring L.A. pop-up where the employees can tell you as much or as little as you want to know about cacti. Marco can tell you about the trees. Must visit, but only open April/May - September/October.
The permanent piece called "Meeting" at MoMA PS1 is an etherial experience of light and color and quiet. Sit and look through the cutout in the ceiling and watch the light change both outside and in. You can't tell what you're looking at until maybe a bird flies by.
Mcgolrick Park at midnight in the snow. Any early morning with all the bums and drunks passed out on Nassau Avenue. NYC still looks best between 3am and 6am, just before the light comes in to shine on all its flaws.