We've done it so many times, we have a fairly regularly routine, which usually includes visits to two San Francisco landmarks I'd like to mention in this post, apropos of a comics-related blog: the Cartoon Art Museum and the Tintin/European character store called Kari'kter on Sutter Street's gallery row.
The Cartoon Art Museum has been in its present space since 2001 and is conveniently located not far from the Market Street/Union Square area of San Francisco. (It's the third location I've visited for the museum over the years!) During the time of my visit, exhibits were in progress on Edward Gorey's design work for the stage show of Dracula; of Disney animation conceptual artist Mary Blair; and Bay Area cartoonist Lark Pen. While I have passing familiarity with Gorey, I otherwise was not aware of Blair or Pen, and I enjoyed discovering their work.
The highlight for me, however, always is the opportunity to view the museum's pieces from its permanent collection. I saw originals from Roy Crane's Buz Sawyer, a Will Eisner Spirit page, a Milton Caniff Steve Canyon, as well as a very early Blondie, Popeye, Gasoline Alley, etc. It's always inspiring and revelatory to see comic artwork in their original state--the opportunity to see them full size and to examine the brushstrokes, use of white paint, etc., gives students of the form valuable insight into the way the methods of the masters.
By the way, another of our traditions when we're in the city is to visit the Japantown center (where we usually grab lunch or dinner) and, particularly, the Kinokuniya Bookstore. This is a terrific authentic Japanese bookstore with tons of Japanese magazines, books, CDs, etc.. There also are many English-language books featuring translated Japanese authors, Japanese art and architecture, cooking, children's books, etc. During this visit, we discovered they had just re-modeled and completely moved all their manga (Japanese comics) to a new dedicated space on the lower level of the mall where the bookstore is located. (In fact, the mall itself has received a much-needed facelift, and "J-town" looks like it's undergone a much needed minor facelift).
Anyway, if you're ever in San Francisco, I recommend you visit these places!