I love, love, LOVE Isopure protein drinks from GNC or the Vitamin Shoppe. The ready-to-drink bottles each have 80 g of protein in a 16 oz bottle. Pretty great! They're SWEET... mostly remind me of koolaid. I like "icy orange" the best.
I'm a gastric-bypass patient, by the way, so my life is currently keeping up w/ my protein count. I've found that the easiest way for ME to stay on top of it is to mix half a bottle of the isopure w/ a crystal lite (matching flavor) and another 8 oz of water or so. That way, I stay on top of hydration and protein. I know isopures are pretty low calorie, and I know they have zero sugar...
One other thing- both GNC and Vitamin Shoppe will sell the bottles individually or in cases- great way to try out flavors!
I do hope this helps, and I hope it has made sense. I didn't sleep last night, so my brain is.... fried... to say the least.