Bathtub Gin
The entrance to Bathtub Gin is through Stone Street Coffee Shop on Ninth Avenue in Chelsea. There's no sign out front pointing you there. You walk past the espresso machines and through the back, and suddenly you're in a completely different place from the 21st century.
The bar opened in 2011 and was built to look like a 1920s gin joint. Dark wood, damask wallpaper, plush leather seating, and at the center of the room, a big antique clawfoot bathtub that the whole place is named after. The cocktail list runs toward the classic end with some inventive originals in the $16-22 range, and the kitchen turns out a full dinner menu if you're staying a while.
On most weekends there's live entertainment, sometimes jazz, sometimes burlesque, sometimes both. It fills up fast, so reservations are worth making ahead of time. The Chelsea location means you get a mix of locals and people who planned a trip specifically for this.