I have family that lives near Baltimore so I'm pretty familar with the Inner Harbor.
If you like seafood or more specifically crabs, Baltimore is known for their crabcakes. You can find multiple places at the Inner Harbor that makes them.
I would also recommend going to the National Aquarium too. It's tremendous! The dolphin show is worth it but be prepared to spend a few hours there.
The Inner Harbor is also home to an ESPNZone. I've only visited the gift shop so I can't give any insight on the food or atmosphere.
Here's a link to a list of more attractions in Baltimore - http://baltimore.org/attractions/
Babe Ruth Museum
Maryland Science Center
Star-Spangled Banner Flag House