I need to gush about what I think may be the best -- and certainly most undiscovered -- sushi places in SoCal: Sushi Wasabe in Tustin, near the intersection of the 5 and 55. Tucked at the end of a mini-mall, next to a donut shop and an auto-parts store. No decor to speak of, and I've walked in at 7pm on a Friday and had my choice of seats. The LA Times wrote about it a few months ago, but even that hasn't seemed to draw a crowd (a sad comment in itself).
They have only sushi -- nothing else. Chef's choice only at the bar, but you can order at the tables -- I recommend letting the chef do his thing. I've eaten a lot of sushi, all over SoCal, and the only place that even comes close in my book is Sasabune on Sawtelle. The fish is incredibly fresh, and enhanced by all sorts of subtle, citrusy sauces the chef mixes up before your eyes. A raw albacore sashimi in sauce to start the meal blew me away. Not cheap, but a lot less than, for example, R-23 -- and a helluva lot better, IMHO.
If anyone knows of a better place for sushi, especially in OC, I'd be glad to hear it.
14460 Newport Ave., Tustin. (714) 505-3496.