Pleasanton is infested with mediocre overpriced Italian-American restaurants.
I would say that Kawa Sushi in Livermore (about 5 miles) is the best sushi in that area:
http://www.kawasushi-inc.com/
There is a good dimsum place in Pleasanton at the Pleasanton / Dublin line. The Willow Tree.
6513 Regional St
Dublin, CA 94568
(925) 828-9111
Have fun.
George
George