C.M.
I realize that with responding to this today, you may have already gone last night...But, we go to Sushi Sakana at Parker/Custer, and after having tried EVERYWHERE else, they are the best. Even better than Blue Fish (although they're pretty darn good too). Sakana is cheaper.
There is a new place that came in up near Preston/121 (on the Plano side), that is a buffet style that has sushi "boats" - the sushi floats around and you take what you want. I went to a place like this in San Fransisco once, so I really want to try them.
My kids love sushi too, and often I opt for the Tom Thumb stuff, but when we go out, Sakana is the best.