Nice lineup of cities! I've been lucky enough to go to 3 of them. These were my favorites, and you can't go wrong with any of them. Of course, it's great to just explore and find your own favorites, too!
London:
Ye Olde Cheshire Cheese,
Cittie of Yorke,
Euston Tap (next to Euston Tube station, just down the street from the British Library, and they even had some American craft beer if you get homesick),
The World's End in Camden Town, the list goes on...
Düsseldorf:
Uerige (pronounced "Yuregga") for sure, then every other brewery in the Altstadt
Berlin:
Bierkombinat,
Prater Biergarten areas that are great are Kreuzberg, Friedrichshain, and Prinzlauer Berg
Wish I could go back to all those places!