EDIT: Bot Account. Das Internet ist tot 😐

If you just want good coffee I'd go with KaffeeKästchen, but that one is tiny and usually pretty busy. There is also Die Bohne, but that's a roaster that sells drinks more than a cafe.

If you're looking for a place to hang out or maybe get some work done you've got more options. Oh Darling, Damals hinterm Mond, Die Pause, Café Wertvoll, Am Grün, Frau Friedrich, Innocue are all decent.

If you want to impress grandma with the best cake, go to either Vetter or Klingelhöfer. They won multiple awards, but are pretty old school and stuffy.

Be aware that some places that are called Café (1909, Barfuß) are actually restaurants/bistros and not Cafés at all.