Great quaint little cafe in Frankfurt called GUTDING (loose translation good thing). Now this is one of the only places where I can recommend as a sandwich place in Frankfurt ( He offers other things) .
He being, Hal the proprietor has created an excellent niche, which could be placed in any metropolis.
Also he does not have that nasty pickle (sauer Gurke) lurking in your sandwich
Address : GUTDING Sandweg 10 60316 Frankfurt Tel: 0178 5590995