I could fill a book with reviews of the trendy restaurants that line 14th Street. While there are more than enough options to choose from, one of my favorites is El Centro. Some bars can get tight but El Centro offers happy hour specials at their large rooftop bar and open seating inside. There is also a more formal dining area where you can order from the full menu.
The happy hour specials at El Centro vary but they usually offer margaritas and Modelo. Taco specials are also available during happy hour but the best deals are on Taco Tuesday. They offer a wide variety of tacos including beef, chicken, fish, and veggie. The waiters are very friendly so if you want a recommendation, just ask! They usually steer me toward beef or fish tacos and I am never disappointed.
El Centro has two locations: one on 14th Street and one in Georgetown. They offer daily happy hour specials from 16:00 to 19:00 and bottomless brunch from 10:00 to 15:00 on Saturday and Sunday.