Sushi is not all about the fish. Rice is also a very important component.
You may go to different sushi restaurants and notice the difference of rice at each place. Each one of us have different tastes too, so it could be a fun thing to go around a few places to compare and find your own favourite sushi rice.
For our sushi rice, we mix couple of different kind of rice, couple of different vinegars, then salt and sugar.
It is important to cook the sushi rice in the minimum amount of water possible. This allows the rice to absorb the vinegar mixture afterwards - This is also to achieve a good texture and taste balance between the fish and the rice.
So normally, you use less water than when you cook white rice regularly.
This is a personal opinion, but I like Koshihikari for regular white rice, and Sasanishiki for sushi rice (less moisture).
Rice used for sake making is a different type (not so tasty to eat but oh so good for sake! How was this all figured out...?). Sake makers try to avoid the rice absorbing water, counting even seconds with a stop watch when washing the rice.
Back to the sushi rice - Sushi rice cooked in the minimum water possible requires some techniques to handle. If you are going to make sushi rolls at home for a party with friends, it may be easier to make those rolls with rice cooked normally.
Well, it's a long road to become a sushi master...