Where to live with twins?

I'm a city girl. I always have been. I was lucky enough to grow up in the beautiful suburbs of Marin but every chance I got I was on a plane to some city (the more exotic, the better). These travels (for fun, school, and work) took me to Madrid, Barcelona, Lisbon, London, Egypt, Mumbai, Bangalore, Seoul, Singapore, and more. Just writing of travels make me daydream of romantic cityscape around the globe.

My travel days are going to be put on hold for a while but my love of cities will remain. Currently we live in San Francisco - and love it! But with low ranking school systems, expensive houses and rent, and shocking ... uh, sites I'm wondering if this is the city for raising twins.

A quick Google search brought up the following cities:
Kiplinger

1. Minneapolis, MN
   
2. Provo, UT
   

BusinessWeek

1. Groesbeck, Ohio
2. Western Springs, Ill
3. Deerfield, Ill
   
4. Echelon, NJ
5. Arapahoe, Neb
6. Waverly, Neb
7. Wilmette, Ill
8. Lackland, Tex
9. Waterville, OH
10. Hopewell, TN

Fit Pregnancy:

1. Boston, MA
2. San Francisco, CA (YAYAYA!)
3. Minneapolis, MN
4. Portland, OR
5. Omaha, NB
6. Denver, CO
7. Colorado Springs, CO
8. Seattle, WA
9. Oakland, CA
10. San Diego, CA

Each survey, and subsequent list, has different criteria ranging from open-ness with breast feeding (something Fit Pregnancy looks at), to schools, to working and raising kids (something Kiplinger looks at).

I think what it comes down to is:

1. Where do you feel safe - where will baby be safe
2. Where are your family and friends
3. Where is work OR where do you want to work
4. What are the schools like (I'm a huge advocate of public - San Francisco is not winning any awards here)
5. Where are you happy