I lived in the SF Bay Area for twenty years. From my own experience and from talking with people who live in other parts of the W Coast, in terms of the US I would say Seattle, for three main reasons:
1. proximity to the mountains
2. great culture and lifestyle in general terms
3. a mountain/outdoor culture and community that I don’t think exists in any other part of the W Coast.
From the little I know, Vancouver could also be a good choice for the same reasons, plus it’s in Canada.