Don't worry, kid, you'll come back after grad school. I did. (Oh, and Pig, wish me luck on the defense.)
(I'm a complete newbie here, so I apologize if this has already been said.) As for Dayton points of interest, I don't know how many of the following parks and such have been mentioned. I'm a public historian, so this is what I think about. I tried to link all of these to their websites.
Carillon Historical Park
Boonshoft Museum of Discover (which I haven't been to in years, but I remember liking the planetarium)
Sunwatch (somehow affiliated with the Boonshoft, I believe)
National Park Site:
Dayton Aviation Heritage National Historical Park (includes The Wright Cycle Company building and the Wright-Dunbar Interpretive Center and Aviation Trail Visitor Center; Huffman Prairie Flying Field and Huffman Prairie Flying Field Interpretive Center; John W. Berry, Sr. Wright Brothers Aviation Center; and the Paul Laurence Dunbar State Memorial)
There's also Glen Helen in Yellow Springs, Clifton Gorge, and others that escape me at the moment.
Not a park, but we have the Dayton Air Show as well. I've never been, but PigBoy went last summer so he can tell you how it is.