What are the most popular student activities/groups?
Duke students engage in a lot of different activities. Durham is one of the "foodiest" cities in America, so going out to eat is AWESOME. Additionally, the nightlife in Durham is pretty fun. Some students don't like it (it takes a sense of humor to like some of the establishments because they are just so ridiculous, such as Shooters II, which has a mechanical bull and a giant statue of a horse in the middle of the dance floor), but it is easy to find a place to just hang out and chill on campus on a weekend as well. Speakers come, and DUU and other campus organizations put on really fun events, such as concerts, water balloon fights, bouncy castles, etc. There are also a multitude of sports events to go to, and there is no experience quite like being a Cameron Crazie.
As far as romance, Duke could be improved - there is certainly a lack of a dating culture at Duke. Students start to settle down sophomore and junior year, but actually going on dates is rare, as are relationships freshman year. Some Duke students go through their entire college experience without having a significant other, whether by choice or no. There is a hookup culture, especially within the Greek scene. Fraternities and sororities are as important as you make them in your life. However, this may change with the new housing model that Duke is implementing.
The Duke student body is open to friends and new people, though as the years go on it gets harder to meet new people. Overall, the students enjoy the social scene, and there is never really a lack of things to do.