Once, I won third place at a sushi contest after eating 16 pieces of sushi (large ones) and drinking 3 cups of sake in 3 minutes! These kind of experience makes you favor sushi a bit less though
sushi grade
finding sushi grade fish isn't easy.. I buy my sushi fish in a certain place where I know exactly when they get the fish.
still you might find this article helpful:
Sushi for me - Sushi University - Choose a good fish
it might help you in you next sushi fish shopping.