Personally I think the best SFO
spotting is the San Bruno Avenue overpass over Highway 101. This is at the departure end of the 28s so all the heavies will scream right overheard. Without a decent zoom this is the best place to be. While Bayfront Park is the most popular, it is the furthest away. Some people have had luck getting up onto the roof of the rental car lot and/or the other parking structure near the Skywest Terminal which offers the same proximity as San Bruno Ave., but a better angle.