There are three starting neighborhoods in Sims 2, each with its own personality. These are:

Pleasantview
The land of soap opera relationships. You can choose to be drawn in to them, or you can ignore them and go on with your own happy little life. Lots of green lawns and square plots of land.

Strangetown
This is the place of UFOs and mystical happenings. If you're into the strangeness of the world, set up shop here. Dusty landscapes and dark spooky nights.

Veronaville
Two families, divided by water. Yup it's Romeo and Juliet all over again, complete with the supporting cast. Lush landscapes with a big river are found here.

Really if you're not doing the built in scenarios it doesn't matter where you choose to build your family, it just means your outside environment is a bit different in each case.

The Sims 2 Tips, Techniques and Walkthroughs