Planning a trip to San Fran with my wife to celebrate her retirement. Staying in Union Square downtown. First trip. Know some of the obvious required must see landmarks ( GG bridge, Chinatown, Fishermans Wharf, Pier 39, Haight Ashbury, Coit Tower, Napa, Muir Woods, Alcatraz) along with planning a bus and boat tour but would appreciate any locals/ frequent SF travelers with advice or recommendations on some interesting different downtown city sights, walking tours, bars, restaurants etc. Thanks in advance for the help!