Today is National Donut Day!
Dunkin Donuts is offering a free donut with any beverage purchase, and Krispy Kreme is giving out one free donut at participating locations (including Penn Station). The free goods tend to run out fast (last year certain locations were out by 10AM!), so get there early.
Check out this Yelp thread for other suggestions on where to celebrate Donut Day, as well as Serious Eat's suggestions.