SF: Pier 39 (used to be a coin-op arcade the last time I was there), Alcatraz (tourist-y but everyone should tour it at least once), lunch or dinner in Chinatown, Exploratorium (science exhibits), concert at The Fillmore, Haight-Ashbury record stores (if vinyl is your thing), Golden Gate Park (comparable to Central Park in NYC), Sunset neighborhood (beach combing), ATT Park for a baseball game. Those are just off the top of the head.