I considered Civitavecchia before I wrote my post, but, I have embarked a cruise there only once. I don't recall anything particularly scenic when we sailed, but, did enjoy seeing the large variety of ships (Med ferries) of companies that I had heard of, but, never had seen.
As a port of call, I have visited San Francisco a few times, but, never embarked a cruise there. For me, and others as well, it's special. Why? The scenic harbor, the city's skyline, and the Golden Gate Bridge!