A vegetarian option for the daring is Handkäs mit Musik, literally: hand cheese with music, a traditional dish where dry, round, low-fat cheese is marinated in oil with caraway and raw onions hence the "music".
Another Hesse specialty is Rippchen mit Kraut, cooked pork chops with loads of Sauerkraut.
Not to mention the original Frankfurter Wuerstchen, which are essentially the same as Wiener.
For pastries, try the Frankfurter Kranz Frankfurt Wreath.
