Restaurants to take business partners to? (Frankfurt)

Hi everyone!

Can anyone recommend restaurants in Frankfurt with great cuisine?

I'm not living in Frankfurt, but quite regularly we need to take out business partners from Asia to dinner in town, during their stopover at FRA airport. Running out of ideas...

Am looking for places with pleasant atmosphere and excellent food.

Thanks a lot for your insider tips to Frankfurts dining scene.
Highly apprechiated!

Best regards, Nadine