It was a wise decision of the Park Inn Hotel at Berlin Alexanderplatz when they built a viewing platform on the roof a few years ago. It seems that still many tourists don’t know about it, but in my opinion, you can enjoy one of the best views over Berlin from up there – including a premium view of the television tower.
I can recommend this hotel to everyone who comes to visit – even though, I as a Berliner never had a room there. But be careful that you book the room on the right side of the building. Otherwise, you won’t see much apart from old communistic blocks of flats.