You want to do this: City bus tours
Do this instead: City bus 100 and 200
Sure, those massive tour buses with the apparently hilarious MC cruising around the city look tempting. Instead of overpaying for a ride around town however, hop onto line 100 or 200 of the city buses, which run along a similar route, from Alexanderplatz to West Berlin’s Zoological Garten. They’re also double decker, they pass basically every cool/photogenic desto in the city, and they don't have a dude demonstrating the German sense of humor.