Let me underscore what Duhey has said.

Most people assume that when they fly into FRA airport and need a place to stay, that they should stay in FRA city. But honestly, Fankfurt is a very boring city.

If you already are in Frankfurt attending meetings, and just need a place to stay for the night, so be it .... you might as well just stay there. But if you are flying to FRA airport and need a place to stay close by, I would head west and go to Mainz. A pretty, quaint city, on the river, a nice pedestrain area downtown, etc, and some great places to eat.

Unless you have to be in the city, don;t make Frankfurt an option.