Columbus is a fast 45 minute drive!
Sorry, the only time I've been to Dayton was when USAIR had a cheap last minute deal to fly there. I picked up a rental car and drove to Columbus to visit my dd at Ohio State.
What do you like to do? One great thing about central Ohio is that it's pretty flat if you like to bicycle. There are loads of great restaraunts in Columbus, comedy clubs, shopping, galleries on Short North (High Street), but all I know about Dayton is how to get out of the airport. It's a pretty nice little airport
Have you googled Dayton?
Mel