It really depends. Personally, I prefer a rural lifestyle. I live in a rather small "town" of ~8000 people. It's actually the largest town for 30+ miles.

Normally, rural areas have lower crime rates. Cities tend to be more dangerous for children as well. Living in a larger city will create a more diverse environment for your child. For example, the demographics where I live are astounding. Over 95% of the population identify as being white. We have literally 13-15 black people in our entire town. That's it. (I believe it's only 4 families). During highschool, we had a single black kid in the ENTIRE highschool. Literally, just one.

But it really does depend on the area, I suppose.