Best worldwide: San Sebastian, Spain. /thread
Next Tier: Tokyo, London, Rome, Paris, NYC, LA, San Diego, Seattle, Vancouver, and of course SF.
Shitholes: too many to list, and i green up in those Maine Township (East/South/West, and North before there Breakfast Club) suburbs - provincial, boring, uneducated, and depressing - they are far from the worst but i miss nothing about them and my lame-ass HS friends that never left the home town are so culturally deprived it would be sad if they ever realized the extent of it. Better not to know what they're missing i guess.