If you ever have the chance to dine at Morimoto in Philadelphia, the chef/owner commissioned his own "brand" of sake's in varying levels of quality.

Generally, the rice used to make better sake is polished multiple times, resulting in a drink that is smoother and less harsh on the throat.

I did a flight of them, and the difference is marked. Sake is also a bargain, with all but the pinnacle types selling for less than $12 a glass (and this is an ulrapremium product).