Went to Berlin in November, a group of 9 of us and had a grand time. Well apart from the Union Berlin Ultras telling us to f**k off and leave before their game ever started.
Travelled on a Friday evening, got the train in from the airport, costs about £3, possibly less. Some bloke decided not to pay and was fined around £100 on the spot. Couldn't understand why he just wouldn't pay the fare given how bloody cheap it was.
Stayed right beside the central station in the Meininger hotel. Very basic, but does the job. Cheap bar inside, bratwurst stall outside.
Saturday we did all the touristy bits, Reichstag/Brandenburg Gate/Holocaust Memorial (close to this there is a Borussia Dortmund supporters bar oddly).
Sunday we were off to watch Union Berlin v Stuttgart, now it is important to mention have two main entrances for their Stadion An der Alten Försterei ground. DO NOT, like us go to the entrance with all the Ultras. It is easy to tell this entrance as they have a little club house thing, if you see that, just keep walking round. There is a little canal type thing that they all stood close to, having a drink, we just walked by speaking away in our group. We got outside the entrance and took some photos before some boy no older than 18 came over and asked where we were from and who we supported. Now as there was 9 of us, and we all supported different sides, one of our lot said "England, West Ham". The boy just said "ok" and walked off. Put us on edge a bit, so we decided to move off, and stand somewhere else. Within a few minutes their ultras started coming through a small gate, around 40/50 of them, we thought we would move out their way, unfortunately they kept walking in our direction. What I can only assume to be their leader walked over and started screaming in German at one of our unfortunate members, he just kept saying "no, no, no" as he has no idea what this bloke was saying. Eventually he started speaking in English and asked who we supported, we tried to explain we all supported different sides, but most of us were from England. That was enough for him, he told us in no uncertain terms to leave, and that we were not allowed to come in. So we thought there was no chance of risking it, and walked back to get a tram, on walking back we looked over our shoulder and found that they were following us. We hopped on the tram and they stood at the doors to make sure we couldn't get off. Eventually the tram started to move, before we realised we had no idea where it was going, so hopped off outside a hotel and got some cabs back to Berlin train station (about £25).
We watched the game in the pre mentioned Dortmund supporters bar and willed Stuttgart on to victory (they drew 1-1). The guy who sorted our tickets told us afterwards that their ultras are sick of being perceived as a family club, and now want to create bit of a reputation for themselves. In all fairness they could of given us a swift beating, but just made sure we didn't come in. So that was nice.
Incidentally the Sunday became the best day, instead of moping about, and being angry, we took the time to go round Checkpoint Charlie, see some of the wall, and ended up in the Lemke brauhaus , which someone else mentioned. It was absolutely quality.
Would definitely go back with the Mrs, felt we missed out on quite a bit, but that will always happen when with a big group. We had a couple cab journeys and found on asking the driver on their memories of the East/West split, and almost all of their reaction to being asked was quite cagey. One told us he was embarrassed and didn't like to talk about it. Would definitely like to find out a bit more about it, very interesting.
PS Union Berlin look to have shat promotion to the top tier of German football