From LHR to SFO, 95% of the time you want to be on the left. It really makes little difference taking off, the views of Iceland, Greenland and Canada are either spectacular if you can see them, or random depending upon the routing. Likewise Mt. St. Helens.

However, the approach to the Bay Area makes a huge difference. Most of the time the plane heads out to the ocean over Pt. Reyes and takes a left turn. You usually get amazing views of the coast line and of Sausalito and then the plane starts a further turn to the left as it's passing the GG Bridge, exposing a panorama of the Bridge, the City and the entire north Bay. Its left turn then takes it down the center of the south Bay with a right turn south of the Dunbarton Bridge before lining up for the westerly landing runways. On final approach you can often see the Campanile at Stanford (if you know what you are looking for) and then rather uninteresting suburbs as you pass Redwood City, San Mateo and Burlingame. However, sometimes the last minute or so of the flight is enlivened by another plane landing on the very close parallel runway - and this is normally on the left as you've approached from the right.

The remaining 5% of the time you don't take the turn over the GG Bridge (but still see it) and instead fly down the peninsula and turn left over Woodside - but you get good views of the City and the South Bay this way also.

Very very rarely (and usually in foul weather) you will land to the East (the 10 runways rather than the 28s) but you won't see anything because of the weather.

So - sit on the left, without question, and avoid the wing if you like views.