I live have flown out of SFO countless times and aside from the Amsterdam Schiphol Airport, I must say that SFO is by far my favorite airport.
The international terminal has a modern airy feel to it and the shops are alot of fun to visit. The Sees Candy shop is a must visit in the terminal when we are in the airport along with the perfume shop right past the security checkpoint. Taking off on the long haul flights are fun too because you take off over the bay and it gives a really pretty view of San Francisco.
The domestic terminal is not as nice as the international but they have a Jamba Juice(my favorite) and a Guava Java which are both delicious drink shops. I believe they have a Peets Coffee which has really good coffee.
Coming into SFO, I alway feel like we are going to land in the bay (we never have) but the immigration lines have never been a problem for me and BART (Bay Area Rapid Transport) has been really nice because it is so accessible and can take you as far out as East Contra Costa County.
It is definately a fun airport to fly in and out of and I will continue to enjoy my flights in and out of SFO.