And I can recommend, not 1st class modern hotels but, two "Pensionen" with charm, style and history in central West Berlin that are affordable:
Hotel-Pension Bella
http://www.pension-bella.de
They have "W-LAN kostenlos" although I have never tried it. AND, at least a couple of years ago, the owner's father had been a Ju 52/3m pilot during the war...
Hotel-Pension Waizenegger
http://www.hotel-waizenegger.de
No internet access, I think, but very nice.
Lennart A