Thomas Sweet is pretty popular with the tourist and 14-year-old first date crowd, which means there’s usually a line. It’s worth waiting in - this is some of the best ice cream in DC in a classic old-timey shop. We like the cones dipped in chocolate, but there are also ice cream sandwiches, soft serve, and an entire counter dedicated to fudge. If you have to run some errands on M Street, this is a necessary last stop.