Cincinnati airport area
If you really like fish and want to leave the airport, take a cab to Mr. Herb's on Petersburg Rd Rt. 20 (Hebron)-- it's practically off the end of one of the runways--maybe 4 miles. Their fish is what they're famous for, but it is a family place that has a good-size menu. And very reasonable.
I'm not sure what the best options in the Cincinnati airport are anymore - but I'd see what's there more so than looking to leave the airport. The immediate airport vacinity isn't so full of options unless you have so much time you want to go further into Covington Kentucky or downtown Cincinnati. Jo An's would be a quick cab ride (http://www.joanjapanese.com/) - but it's definitely more on the fancy side.
Concourse B has the most food options, and to the best of my memory Concourse A has Graeter's ice cream. If you want to do an "ultimate Cincinnati meal" you could do Gold Star Chili and then Graeter's - but after eating that meal, I'm not sure I'd personally want to get on an airplane.