Saku has always delivered in my books with its unique rolls and great starters.
I personally enjoy the baked rolls offered here - the Island roll at $12 which has avocado, prawn tempura, scallop, and yam is delicious. They are a bit heavy compared to standard rolls, so I'd recommend ordering a few and sharing between friends for some variety.
The chirashi don at $25 is a great dinner option. The fish and uni is very fresh and worth the price you're paying.
In terms of sashimi, the best value would be to order their take out offers. We found it strange that they didn't offer any "boats" at the restaurant, but had them available for takeout. We ordered a 50pc sashimi platter which was $55. It was fresh and great quality fish.
Overall, Saku is an excellent sushi pick in general (especially since they offer items like bibimbap for anyone who isn't a sushi fanatic) but maybe go elsewhere if you're looking to gorge on sashimi.