One of the best views of San Francisco is from the 36th floor of the Grand Hyatt San Francisco near Union Square. The tip is being there on a clear day. Here is a 44 second video taken from the 36th floor Grandviews Restaurant and Lounge.
One travel tip I have picked up over the years, primarily through my frequent stays in San Francisco, is to visit hotels with high floor and rooftop bars for great panoramic vistas. One drink, then move on to another place is an affordable way to experience a nice hotel and location – after taking plenty of photos of course.
This video is from 2009. Downtown San Francisco has not changed much since then, except the Grand Hyatt has been completely remodeled and there are some new skyscrapers South of Market (first view in video).