Friends stayed at the Adlon for 2 days. The room they got was one with the worst views ever. Service was good but slow, although the gave very good tip and ordered a lot of room-service, laundry, etc. Seemed to them if you dont stay for longer and if you dont book at least a Junior Suite, you dont seem to be important/valued for them at all.

Best choice in Berlin in my opinion is Rocco Forte Hotel de Rome, followed by the Ritz Carlton (at Potsdamer Platz).

Also pretty good at Potsdamer Platz are the Mandala and Hyatt. The Marriott Potsdamer Platz is the worst choice,... the rooms only have see-through curtains, so you cannot darken the room and there is the Ritz and lots of office buildings next to it.

Wouldnt recommend the Interconti in Berlin. It's old, very old building from the 80s and has only been refurbished partly. However, it is said to be the safest hotel in Berlin, lots of politicians stay there (just in case youre expecting a war to start during your stay )

Hilton looks good from outside and lobby, but havent stayed there,... it has a pretty good night club in the basement though.