Rock Bottom Grill is probably your best bet. They brew all of their beer in-house (and I haven't had a bad one, tbh) and their food is pretty damn good. I almost exclusively get seafood when I go out, so I can't tell you about their steaks, but their lobster and shrimp tacos are probably the best things on the menu.
Its also right in the middle of Fountain Square, which is the heart of downtown and its a great atmosphere.
http://www.rockbottom.com/cincinnatiPS: If you want to have good cincinnati chili and you're in town for more than a day, I'll meet you up at Camp Washington if you want.
PPS: Don't go to Hofbrauhaus. Apparently due to having 8 or 10 assaults on the peremisis in the past 5 years or so, the state of Kentucky took their liquor license away for 50 days (starting about 2 weeks ago).
EDIT: There's also a bunch of fancier restaurants in the same area. It all depends on how much you're willing to spend.