I had several inexpensive sushi meals near Tsukiji market and another at a counter in the Ginza train station, all of which beat 99+% of the sushi meals I've had in the US.

We also went to one of those amazing, reservation-needed places, but were arranged by a local there.

I strongly suspect that it's about as hard to find good sushi in Japan as good Italian food in Rome. My advice is to get out of the hotels and onto the streets and don't be afraid or ashamed to eat at a place without English menus. Point at the pictures if you must, but I didn't have a single bad meal experience there.