I had the pleasure of staying in Berlin together with some family for an extended weekend (May 21st to May 24th) and what a city! Even though I've had the pleasure of visiting many great cities around Europe and around the world I had never been to Berlin before. All the good things said about Berlin turned out to be true.
It's a historic city but also a modern city and a beautiful city. It feelts like there's constantly new things to see.
We stayed at the Marriott Berlin at Potzdamer Platz - A really nice hotel 5-10 min. walk from Brandenbuger Tor.
For those of you who needs a little inspiration please feel free to watch this small clip showing some of the many impressions from our stay: http://www.youtube.com/watch?v=PslK9KXzk6Y
(I'm sorry but certain countries have problems with the music in the clip)
If you are considering going to Berlin I would recommend you to go. Our company of 6 people ranging from 16 to 69 years of age all agreed we'll have to go back another time.