Wasabi! Watch out when Eating in Japan
Most chefs will put Wasabi on your sushi
Blue colored fish like Sanma and Saba are best without Wasabi. Try ginger with these.
If you dont really like having a lot of wasabi in your sushi, please make sure you ask the Chef "Wasabi wa karume de". This literally means, "Please go lightly on the wasabi". Or, you can ask for "Sabi Nuki" which means they wont put any wasabi in the sushi at all. However, the wasabi flavor actually really brings out the slight vinegar taste to the rice as well as the natural flavor of your fish.
There are some types of fish that dont work with wasabi at all so if you are served a blue colored fish, try it without wasabi. You dont need to dunk everything in the shoyu wasabi mix you have in your little dish.
Sushi is a very delicate type of cuisine and is actually eaten in a certain order. Decide your budget and take a chance on real Japanese sushi!