I frequent Philz on 24th. It seems like there are always developers there. Javalencia on Valencia is usually pretty quiet. That being said, neither has the best coffee. Also, Philz isn't quiet if you need it. It depends on what atmosphere and other attributes you need to code to offer a true recommendation.
Java Beach cafe (on La Playa at the beach) has awesome sandwiches but is normally crowded. It's 100 yards from the beach for nice breaks and thinking about problems.