The original series was set in Hawaii because in 1968 the state was considered
exotic and the Governor was actively pursuing Hollywood to shoot there. While
it is a standard police procedural, at the time no show has been set there. The
locale tells you a lot about the stories and the people. The stories set there are
different than the ones set in (for example) Las Vegas (CSI:) or New York (CSI:
New York). Of course with the remake it would have been nuts to set "Hawaii
Five 0" in Toronto.

A police procedural can be set in any location. I no the in 1968 the exotic
location was one reason the creators chose Hawaii. So if you are thinking that
a previously unused city would help attract viewers to your film then you, the
producer, can make that decision before you hire the writer. I really do not
think the audience cares one way or the other. I believe the potential viewers
are much more interested in the story and characters.

But in answer to your question; if I had ONE city to choose I would choose
Santa Barbara, CA.

I thought the original Hawaii Five-0 was set in Hawaii. I agree the story and characters are far, far, more important, but an exotic locale can be important - the James Bond films uses exotic locale as eye candy, from what I can see.

What's so good about Santa Barbara? Does Summer Glau live there?