There's a lot of good sushi on and around Valencia Street. And a lot of good service. (Tokyo A GoGo, surprisingly enough, even though it has a high design interior, is surprisingly friendly.)
However, the top of the tops is Yo Yo's. The best service in town comes from sisters Jennifer and Jessica, who will serve up delicious sushi with fun conversation and a great sense of humor. Yo Yo is also a great place to take a big party -- it's rarely crowded, and their are plenty of tables to defeat the usual ""sushi wait"". Go there. Now.
Pros: Fun, Uncrowded, Not too loud