Rinse the sushi rice under cold water until the water runs clear. Cook the rice in a rice cooker according to the manufacturer's instructions.
In a small bowl, mix the rice vinegar, sugar, and salt until dissolved. Once the rice is cooked, transfer it to a large bowl and gently fold in the vinegar mixture. Let the rice cool to room temperature.
Place a sheet of nori on the sushi mat. Spread a thin layer of sushi rice over the nori, leaving a 1-inch border at the top.
Arrange strips of cucumber, imitation crab meat, and cream cheese along the bottom edge of the nori.
Using the sushi mat, carefully roll the nori over the filling, pressing gently to form a tight roll. Seal the edge with a little water.
Use a sharp knife to slice the roll into 8 pieces. Repeat with the remaining ingredients.
Serve the sushi rolls with soy sauce, pickled ginger, and wasabi, if desired.