I originally found out about Cafe Grumpy (embarrassingly enough) from the TV show Girls. Turns out, it is a real place and even better, it has some of the best espresso in NYC. They roast their own coffee and their most recent espresso blend--Heartbreaker espresso--is heartbreakingly amazing. Also, the people that work there are far from grumpy. In fact, every barista that I have encountered at two of their four locations that I visited was spot on in friendliness and coffee knowledge. And in pulling a dank espresso. Their Heartbreaker espresso is a blend of Colombian and Ethiopian and is sweet and somewhat fruity (their description is "honeysuckle, tangerine, brown sugar"). Although I haven't visited their original location in Greenpoint, Brooklyn (where Girls was filmed), the locations in Chelsea and the Lower East Side were fantastic. Side note: The Lower East Side location is great if you are wandering around Chinatown and need a pick-me-up but this location is very small and only has standing room or a window seat. The Chelsea location would be more ideal for studying (although no WiFi) and has a great back garden area when the weather is nice.
Note: No WiFi at any location (except at Greenpoint, Brooklyn). No public bathroom at the LES location. The roastery is located in Greenpoint, Brooklyn location.
Recommend: The bakery is located at the Lower East Side location and their pastries are pretty darn good.
Vibe: Very focused on the coffee, traditional coffee shop vibe (hence the no WiFi)
Espresso Rating: 9.5/10
Overall Rating: 9/10
Hours: Chelsea- Monday-Friday 7am-8pm, Saturday 7:30am-8pm, Sunday 7:30am-7:30pm; L.E.S.- Monday 7am-6pm, Tuesday-Friday 7am-7pm, Saturday 7:30am-8pm, Sunday 7:30am-7pm