Café Karin, on Grosser Hirschgraben opposite the Goethe House, has been Frankfurt's archetypal student-and-journalist breakfast café for more than thirty years. The breakfast menu is enormous — every variation on the German Frühstück you can imagine, with combinations named after writers and journalists — and is served all day. The cake counter is reliably good.
The café fills with regulars from opening at 9am and is busy through lunchtime; come early or in the lull mid-afternoon. The walls are covered with old newspaper cuttings, posters and photographs, and the wooden tables and rattan chairs have not been touched since the 1980s. Free Wi-Fi, decent coffee, prompt service. Grosser Hirschgraben 28.