Just until recently this place used to be one big old Aphoteke (Pharmacy). They have kept the Apotheke's dark wood Art Deco charm to use in benefit of great coffee and fantastic brunch (try the french toast and you'll see I'm not lying).
25 years ago my father used to work here. I know they have a garden on top of the roof. It looks like a big spaceship, I love the futuristic design it has so many little details, I never get tired looking at it.
A very good reason to travel West: the C/O, next to the formerly infamous Berliner Zoo tube station, is an awesome museum dedicated to photography and visual media. Previous exhibitions include Larry Clark, Martin Parr, Anton Corbijn, Annie Leibovitz and Stephen Shore.
The typical Berlin winter is biting cold and grey. In combination with the hardness of the city and the angry natives, it feels like a hostile area. Why it's worth experiencing it? Because that's the way this city is.