This one came from the readers of Leasure + Travel magazine and the link is to an article about it in Time Magazine. I expect the results to be some what controversial.
San Diego is ranked 18th out of 20 ahead of both Seattle and San Francisco but behind a surprisingly long list of other cities which aren't exactly well known as culinary hot spots. I suspect the biases, and east coast centric reader base, of the readers of Travel + Lease Magazine are showing.
Still, they give a good break down of scores in a number of different catagories and their methodology seems pretty sound other than the obvious problem with sampling bias inherent to self selection by poll respondents.