Believe me, you don't want to live in Zehlendorf, Dahlem or any of the areas listed above. Stuck up doesn't even begin to describe the people living there. Everyone lives in a tiny house, surrounded by a security fence (despite being in a very low crime area) with a buzzer system on the front door. It's what Germans call country living. I always found those places really creepy.
Basically, they are West Berliners. The types who think they are God's Chosen People simply because the Americans rescued them from the Bold Bad Commies after the War. They even look down on their East German brothers as inferiors and think the BZ is quality journalism. The types who scream if the train is 0.0000001 seconds late. I always found them disgusting.
If you want nice country parts of Berlin, I suggest Gruenau or Schmoekwitz, or somewhere rural on the East side. It's just way more relaxed and laid back and people are more natural.
Downsides: you definitely need to speak German and there are more than a few crazy Nazi types roaming around.