Ditto. If you're flying in with a major airline and airfare is your primary concern, however, SFO might be your best choice, since it has more wide-bodied jets, more frequencies and usually have lower fares.

But otherwise, I would vote for OAK, hands down. Yeah so it doesn't have all the nice amenities like SFO has, but if you want a simple airport to land into and take off from, and all you do is walk straight to the gate, OAK is very efficient. At least you don't have to go very far for rental cars either.

Hope this helps!
Jamester