With its abundance of lounges, bars, and a concert venue, South End’s growing nightlife district had a void until Marigny Dance Club opened last year. It’s a place where you can dance like nobody’s watching. But at this popular gay nightclub people are watching: the dance floor fills up Thursday, Friday, and Saturday nights, and this is a place to be seen. You don’t come here to stand around—if the bass doesn’t move you, the light show will leave you hypnotized.