Das Stue is a beautiful design-led luxury hotel with 78 rooms/suites, the building was the former Royal Danish Embassy. We've stayed there in an Embassy Room with balcony and enjoyed this luxury hotel. It's different from the others mentioned. Location wise it's overlooking the Tiergarten within walking distance of the Kurfurstendamm. F&B is a strong point here too, very memorable. A true luxury boutique property with interior designs by Patricia Urquiola [public spaces] and LVG Arquitectura [the rooms].

Our stay at the Grand Hyatt Berlin was flawless, beautiful design in our Grand King Room, gorgeous lobby, efficient and friendly services and overall a beautiful grand property in good location within walking distance to the Brandenburg Gate and near to the Postsdamer Platz. F&B by the way was also memorable. While some see the Grand Hyatt Berlin as an upper-upscale hotel, for us at least it's a true luxury hotel designed by Tony Chi.

We haven't stayed at the Westin, but we've had a look, it has a gorgeous location in the "action" of the tourist areas most in demand and it offers a stunning atrium. It's a Westin branded grand hotel and I guess it's geared more towards business, but could be good for tourists too. Interesting opening info: The hotel was opened as the Grand Hotel Berlin on August 1, 1987 by East German leader Erich Honecker as part of the city-wide celebrations of the 750th anniversary of the founding of Berlin. It was only open to foreign guests, as it did not accept East German Marks, only Western hard currencies.
See:https://en.wikipedia.org/wiki/The_Westin_Grand_Berlin

While the Hotel Adlon Kempinski might be the most famous hotel on your list, it's iconic and probably the most famous hotel in the whole of Germany for some, we enjoyed our stay for the most part in an Executive room which felt large and traditional, but we'd a few service inconsistencies [incl. wrong items charged on our bill, despite they said it's waived it wasn't] which marred our impression/feel about this property, while the location is superb beside the Brandenburg Gate, this also means lots of people in the lobby, it's a large property /385 rooms/ and especially the check-in areas and lobby/atrium were always busy when we walked trough. It's an efficient grand luxury hotel, but it wasn't the "warmest" nor "the friendliest" hotel IMHO. F&B was good, but yet again we didn't feel the "warmth" at this property, lets say it was more efficient and good, rather then super friendly and outstanding.

Edit: There's a building site right now at the Hotel Adlon Kempinski Berlin [as reported on TA] incl. the main entrance/lobby areas. [Sep. 2016] This could stretch into 2017. They refresh certain areas of this iconic hotel in anticipation of the 10 years "New Adlon" celebrations in 2017. The hotel was re-opened in 1997 and was since then even featured in a German TV Documentation series/behind the scenes documentation which made it for some even more famous, in the meantime the hotel became of course even busier with visitors, all of them want to have a look at this grand hotel by the Brandenburg Gate. While lots of visitors aren't a bad thing at all, but we found their people flow through the lobby influenced actual staying guests in a somewhat negative way.

In regards of the Waldorf Astoria Berlin, we haven't stayed but we walked past the property, it's located in a modern high-rise, we don't like the location, the hotel is located in Berlin West, which is actually a good thing IMHO, but it's located on a traffic island with strong car traffic on several sides of the hotel and it's busy there in this area which feels more "medium scale" than "upscale" to us. This marred our view about this hotel, but our understanding is once inside all should be good and luxurious again, for some this hotel could be worth it. Depends IMHO.

Cheers & Safe Travels. ^