Greenfield is a great area, and safe. It skews a lot older, so it depends on if you want peace and quiet, or access to nightlife.

Greenfield is also pretty big, but depending on where you are, it's easy to walk from there to Oakland or Squirrel Hill. Also handy access to the Waterfront for big box stores.

I lived there for seven years, so let me know if you want more details.