You'll find plenty of open space (parks, hiking trails, etc) and community activites (parks and rec, sports and more), as well as clean, well-kept environment. Prices in Santa Clarita are significantly less than you'll find in most Northern CA areas as well.
Visit my blog at http://SantaClaritaRealEstateBlog.com and do a quick home search to see if the area and the home prices will suit your requirements.
The diversity, educational opportunites and artistic opportunities are unparalled with anyother city in California.
I will definitely go with Novato in Marin County, just north of San Francisco. http://www.sylviasellsmarin.com/MarinCounty#Novato
The city has great schools, wonderful outdoor environment, is safe, friendly and even though has 50,000+ population, it also has a very nice small town feel; you almost feel that you know everbody - at least in your part of town.
The schools have a lot of extracurriculum activities - music, performing arts, robotics, sports, ..etc, keep kids pretty busy.
The weather is mild, kids can walk to and from school. They make tons of friends. Parents are supportive and caring. We bend together to help our students.
The town is also close enough to San Francisco for you to enjoy all that a city can offer.
Here are a couple of articles for you!
Stop by and visit, you will love it .