Lori - the Montgomery Inn Boathouse (right on the river - about a mile east of the stadium) would be ideal for Saturday night. Should not be so busy that we couldn't get a group in there with more than a normal wait, especially if i were to call a few days ahead and make reservations.
However, if this is the first time that most of you have been to Cincy, somewhere on the -other- side of the river might be better in order to take in the skyline and what not.