Best restaurant experience in Köln?

Next weekend I’m taking my girlfriend on a surprise trip to Cologne.

On Friday night, I want to take her to a cozy restaurant with great food. I was thinking about €60-€80 per person.

It seems like there are so many options. What has been your best experience? Which restaurant would you definitely recommend?

Edit: I’m in general interested in your best experiences, our personal preferences are fish or vegetarian options however. We love all kinds of cuisines, this time I imagine the restaurant a bit more fancy though :)