Yossi Milo is, in my opinion, the most dynamic and eclectic of the photography galleries in NYC. From portaiture to architecture to experimental digital sculptural giant animals to street photography, they show an endlessly exciting range of work. Some of my favorite recent shows include Simen Johan's mythical beasts, Ezra Stoller's architectural photographs of the TWA terminal, and Sze Tsung Leong's huge cityscapes.
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 remember when I saw Shadows, by Andy Warhol in that big room. I was sitting in a sofa, and felt asleep. When I woke up it felt incredible. When my friends come to visit me it's a place where I like to go all together.