Re: Dayton Area
Looks like you can live outside of the city limits. Kind of depends on what your looking for. There are some nice areas up north, but a decent enough drive into town (I'm thinking Troy, Piqua, Tipp City, Clayton, etc...) so for a little quicker commute, Kettering, Beavercreek, Centerville, Miamisburg or Springboro are your best bets.
I know you don't have kids, but if you're looking to buy a house, schooling long term could be an issue. None of those systems are terrible, but Centerville is probably the best. Springboro has had a bunch of levee issues trying to get funding recently. I don't know enoubh about Beavercreek, but I imagine its pretty solid, Kettering is a mix of everything, upper class, middle class, lower class more so than the others, and is probably the most diverse (not that anyone would really call any of those areas diverse)
As far as entertainment, living up by the Green (Beavercreek/Kettering) may be your best bet. Some decent enough bars, restaurants, movies, etc... Springboro is probably the most family oriented in that I don't recall ever going anywhere in Springboro to hit bars or anything. Don't know how old you are, but that could affect where you want to live.
I graduated from UD, but I'm not sure what kind of information you want. Campus is located on the edge of town, near Oakwood (which would be the 'old money' part of the area), but also near some old run down crackhouse type areas. However, the city/UD have done a good job cleaning up some of the outlying ares of the campus such that students can live a bit further out. They've also poured a lot of money into development around campus both in facilities and dining establishments along Brown street. The campus has changed quite a bit. If your thinking of going to UD for Grad school, there are some decent apartments just off campus a bit or rental properties. You probably don't want to live in the middle of the Ghetto (student neighborhood), but there are houses/rooms/apartments to rent along the outskirts of campus that would allow you to feel like your on campus a bit. Its a pretty friendly walking campus, so that if you live close to campus, you can walk to/from your classes most days.