Fallbrook area is definately a nice place to settle down. It is on the very outskirts of San Diego and would be considered rural out here. Its a little bit of a drive to get to shopping though. The land and rolling hills are very nice.
Temecula is northeast and you will find a ton of deals as this is one of the hardest hit areas in all of Southern California. You can find land in and around the Wine Country areas. Temecula would have more shopping closer.
Certain parts of North Escondido may be an option- One are called Hidden Meadows seems to attract retirees.
San Marcos and Vista are going to be a little more San Diego proper and you will also see increased prices.
You may want to find a free home search service that will let you search the MLS for these areas. A good one that I have used is
www.sandiego-home-search.com but search the internet.