This is not a list of all the coffee shops in Berlin, or even all the coffee shops worth going to. It is only the ones with exceptional espresso or drip; there are numerous cafes I visit not listed here. It also doesn't include shops I have yet to visit, though my list these days is fairly short.
If you are in Berlin for a weekend, consider this a good list to pick from. If for longer, do some exploring of your own. I don't speak very much German and I try not to travel more than 30 minutes for coffee, so I'm probably missing out on some worthy places.
Yell at @hazzen if you would like to file a complaint.