San Francisco's twin city is right here in Cape Town. You have the beautiful bay and ocean, steep, hilly streets, diverse and well preserved architecture, a lively arts scene, great food, a cold fog that hovers over the city, wine country literally next door, and a laid-back vibe. If I had to call another urban place home, this is one that I'd definitely put at the top of my list. Just a few things to seal the deal: good public transport so that I can leave the car at home and better service in the restaurants - lunch can easily take 2 hours and even after those 2 hours, you have to hunt your waiter down to pay the bill.
Bo-Kaap's colorful Georgian homes
Looking into the City Bowl from Signal Hill where we sampled some Cape Malay cuisine at Noon Gun
A yummy, healthy lunch at The Kitchen in the Williamsburg-ish, artsy Woodstock. 
The plant-knowledgeable Dot giving us a cycad anatomy lesson
Boulders Beach - home of the African penguin
The "tablecloth"
Outside Franschhoek, at the entrance of the La Motte Estate
The Cape of Good Hope - the most southwestern point of continental Africa 
Chapman's Peak Drive
Sunset at Chapman's Peak