For a long time Vienna was lacking in really good nightlife destinations. But in the last years the city is tacking up the pace to citys like Berlin or London. The scene is not quite as big as it is there, but it is on the right track.
Unfortunately, there is no real area for nightlife in Vienna, because the clubs are spilled all over the city. But still there are some hot spots, e.g. the underground clubs at the U6 metro line between stations "Josefstädterstraße" and "Alserstraße", the Danube channel, the Prater area and the hip 7th district.