A group of military couples are planning a a reunion in Germany in mid-September, 2018, and we want to visit Berlin (most of us for the first time). We are looking for a reasonably priced hotel, maybe in the former East German side, near important sites to visit.
ruth,
If you have a Library nearby, I'd suggest having a look at the RS Germany guidebook as there are listings there for good hotels in a variety of price ranges and in different parts of Berlin. You might want to pack along one copy of the book on the trip, to plan sightseeing.
If you don't mind staying in the area near Bahnhof Zoo, I would highly recommend Pension Peters. I'm sure your group would enjoy the fantastic Dicke Wirtin's Pub, which is just across the street from the Pension. As I recall, the Schwarzes restaurant a few doors down from the hotel is open 24 hours.
Second the Pension Peters with the best host, Euwe. Easy transport with a bus to the Zoo Bahnhof outside the front door, or the S-Bahn at Savignyplatz a couple blocks away. Nice breakfast and a pleasant courtyard in the back.
Archotel John F. It's about as central as you can get, in the former east, and it's a botique hotel. It's a little higher end than I usually stay, but really good value for the price IMO - booking this far in advance you can save a little and get a room from 125 euro.
If that's too much, I'd still recommend that area, as it's walkable to a lot of the big sites and has very good public transit connections. People on this forum seem to prefer staying in the West of Berlin, I don't understand why at all.