Flavor of the Month Shake ($4.99) at BGR: The Burger Joint
Forgetting for a moment that you've just stuffed your face with a burger, there are few places more appropriate for a milkshake than a burger joint. BGR offers a small, simple selection of shakes made from Giffords or Breyers ice cream. You can choose from double chocolate, vanilla bean, strawberry, or the flavor of the month. For August, the special is Key Lime. BGR's shakes are satisfyingly thick to the point where you may have to double up on your straws. Made with Florida key limes, crushed graham crackers, and vanilla, the Key Lime shake is essentially a tangy key lime pie in a cup, without being overly sweet. BGR is located in Dupont Circle, but has several locations throughout the MD/VA area.
Peaches N Cream Shake ($5.50) at Burger Tap & Shake
BTS offers slightly more elaborate shakes than BGR. With a signature BTS shake made with Butterfinger, Twix, and Snickers, the inclusion of an option with the slightest pretense of health consciousness is refreshing. The Peaches N Cream is thick shake made with fresh vanilla bean and substantial chunks of peach throughout. The sweet punch of the peach complements the creaminess well. BTS also offers several spiked shakes (dubbed, "Shaketails").
Oreo Shake ($6.49) at Ted's Bulletin
In addition to burger joints, the milkshake's other natural habitat is the diner. Ted's Bulletin, from the people behind Matchbox, in Capitol Hill (just blocks from the Eastern Market metro) is modeled after the classic American diner. Old-timey touches abound and the same sensibility is applied to their milkshakes. Made with 3 full scoops of vanilla ice cream, 2 spoonfuls of crushed Oreos, and a little half and half, the Oreo shake is a classic no-frills shake. Not muddled by superfluous ingredients, you can easily discern the vanilla and Oreo flavors. True to Ted's Bulletin's theme, it's like a milkshake out of your childhood.
Spiked Caramel Macchiato ($9.50) at The Tombs
A popular neighborhood restaurant just outside the Georgetown campus, The Tombs (from the people behind Clyde's) is home to the best spiked milkshake we tried. Made with Van Gogh Dutch caramel vodka, Stoli vanilla vodka, and mocha ice cream, this shake is a frothy mix of dessert's best flavors. The coffee cuts the sweetness a bit and the shot and a half of vodka adds a little heat and well-integrated flavor.