The Hilton has a nice bar in the lobby called The Orchids at Palm Court. It has a serious art deco style, if you are into that type of thing.
http://www.orchidsatpalmcourt.com/
You'll want to visit Over-the-Rhine(OTR) as it has been built up significantly. Getting into the restaurants in a timely fashion in the evening is difficult but most of them are worth it.
http://kruegerstavern.com/ has good burgers.
http://www.bakersfieldtacos.com/ has good tacos but be prepared to wait.
http://revolutionrotisserie.com/ has great fried chicken and is off the beaten path.
http://www.gomezsalsa.com/menu/ has late night walk-up taco window that is always packed but delicious for drunk food. Their turtle is probably my wife's favorite food. There are a bunch of other restaurants, but these are some of my favorites. Happy to give advice on any others you might have in mind.
As for breweries; Rhinegeist(OTR), Taft's Ale House(OTR), and Christian Moerlein(The Banks) are all within walking distance and are good choices(in that order IMO.) I like The Lackman(OTR) if you are looking for just a bar.
If you like ice cream, try
http://www.graeters.com and get the black raspberry chip. I don't think it is as good as most Cincinnatians do, but it is good.
If you want to venture outside of the city, 50 West is a nice brewery that is a straight shot down 50 east and about 20 minutes out of downtown.
There are a bunch of cool little shops in OTR, but stop at
https://www.rookwood.com/ across from Bakersfield. It is a cool little pottery shop.
If you want to stay closer to the Hilton, check out
http://www.21cmuseumhotels.com/cincinnati/ and its bar. Very cool art. Across the street is NADA, another place to get good mexican food, but more of an upscale place.