"Shamrock Shake town, fortunately there are a few alternative for getting your green shake on in the city...
GAME CHANGING UPDATE!: Gothamist is reporting Shamrock Shake sightings at the Union Square McDonalds! But in case your local branch doesn't have them here are some alternatives...
Option 1) Peppermint Patty Custard from Shake Shack: I haven't had the Peppermint Patty flavor from Shake Shack, but it sounds fantastic. Available at both the Madison Square Park Location and the Upper West Side. Warning...normally the Shake Shack doesn't do shakes with their custard of the day. Not sure if there is a St. Patty's Day exception, so just steel yourself for the possibility of a cup of custard rather than a shake.
Option 2) Mint Chocolate Cookie Shake: Mint Chocolate Cookie is one of my favorite Ben & Jerry's flavors. If you're headed to catch the St. Paddy's Day parade you can nab one of these in the concourse at Rock Center. Ben & Jerry's is all into natural mint so BYO food coloring.
Option 3) Mint Chocolate Chip Shake from Chinatown Ice Cream Factory: Love, love, love the Chinatown Ice Cream factory. You can get a shake from any of their flavors and they usually have mint chocolate chip in stock. If they are out of mint, you might venture down the street to the Haagen Dazs on the corner of Mott and Bayard.
Option 4) Matcha Shake from Jamba Juice: Who says that your green shake has to be mint flavored? Jamba Juice makes a creamy matcha shake.
Option 5) Make your own at home: Check out this recipe from the the February Daring Baker's Challenge. Makes a mean mint ice cream and an even better mint shake.