The quality of rice depends on the stock it originally came from. In China, it's just the long grain ( not as long as basmati ) and the short grain ( similar to that of Japan and Californian rice). When cooked, the texture is different. Chinese like their rice a little starchier but Indians prefer basmati which has less starch. When you eat those at restaurants, they are mostly medium grade. The good ones have a very nice aroma when cooked and holds together while poor quality ones are drier when cooked. Poor quality rice are used often for fried rice since it becomes crunchier when fried adding to the texture. So it depends what you want to cook. Point to note: the starchier the rice, the more sugar content there will be. Unused carbs converts to sugar which results in fat deposits and also explains RoyceH's disgust for pot bellied men during summer!

as louis says, different rice will have different properties. That being said, the differences in rice taste between China and India, the high consumption of rice is a major part in the record high number of diabetics in both countries. 

Also, cheap rice, could be grown in soil with more heavy metals than other rice. If you want good stuff, get some Thai rice.