WUK

It depends on what is going on that night, but this place rarely disappoints. The courtyard is amazing on a nice evening.

Concerts there are usually great; I have never had any problems with queue-jumpers (there are actually much worse places in Vienna when it comes to that).
The real highlight in my opinion, however, is the inner courtyard. I love the old brick walls and the overall laid-back atmosphere there.

I saw a great live concert here last night. The location is nice and the sound quality was great. I just wish they would ban smoking and §%$ing Austrian queue-jumpers.

WUK offers a lot of different activities. I can only really comment on their disco. A lot more laid back than Flex, WUK has a new mixing board and an amazing (semi-recently updated) sound system. Their Friday "Crossing All Over" club is an alternative to Flex's "London Calling" playing about the same style of music. Regular drum and bass parties and post-punk/elektro concerts are usually acceptably priced, whereas the bar is not. WUK has ingeniously rented their bar out to a private company which in turn charges astronomical prices for ridiculously small servings, for example EUR 3,10 for a 20 cL cola.