Japengos in La Jolla is really nice, but pricey. If you've got the bucks.. I'd say go there.
Places that i'd recommend that are near the hotel where cybernet will be are.
Sushi Ota
Surfside Sushi
Saska's Sushi
Those are my favorite ones in that area. I haven't been to any places in downtown SD. I'm sure there are some really good ones downtown seeing that most of the other restaurants I've been to down there have all been great.