Great post. I have to agree with
R-23 and
Ita Cho as being among the best
sushi in LA. I've found the sushi at Katana to be dissapointing, but great atmosphere and as mentioned, great Robata bar. If you go to
Koi it is strictly for the scene - I found the sushi (while good) to be worse than every place listed in this post that I've visited (about 90% of them).
A couple low key suggestions: in J-Town, try
Hamakawa - zero ambiance, but *excellent* sashimi and very inexpensive. Near Melrose and La Brea, try
Azami - it's a strip mall type place, so again without ambiance, but excellent fish. They also have female sushi chefs - very uncommon.