Was at Hertha's game at the weekend against Hoffenheim. Hertha needed to win and hope Koln lost to stay up so the stadium was reasonably busy (53,000 if i remember). The atmosphere was amongst the best I've ever been to with the ultras going crazy for the whole game - could show a thing or two to Scottish fans!
Took us about two hours in all to get from the centre out to the stadium via a whole load of changes on the U bahn and in the queues (as somebody mentioned earlier) are huge and they pat down everybody!
Good night out too, although again big queues for the watergate (apparently really well known!?) club!