Fortunately for the OP, there aren't any grizzly bears or alligators in SF, Seattle, or Denver. Just a few mountain lions at best. Of course, SF does have COYOTE. www.walnet.org/csis/groups/coyote.html
Ok, I'm not moving to san fran. Too expensive. I'm pretty familiar with Denver. I'm leaning towards Seattle, and have been there several times. The light rail is in the works, so that will soon play a big part in my airport commute. With that in mind, what does every one have to say about seattle? Where would you live in the seattle area? Remember, airport commute.
I think the Cinerama theater influenced my choice a little.