Tenax has earned a reputation as being one of the best spots for hearing famous DJs (easy to keep track of upcoming names on their website) and hot house music. The crowd is largely Italian, unlike so many of the more centrally located night spots in Florence.
Head here if you want to get a glimpse of how hip twenty-something Italians spend their weekend nights—or just have a good time yourself. You won't find the customary crowd of older men preying on study abroad students or anything like that (all too common in Florence). People make the taxi trip because the music and ambience are worth it!