i just found one that I think is tasty - it's Rainbow Light's chocolate protein powder. It has spirulina and other good stuff in it! It's vegan, which is what I look for, and doesn't have any soy (rice based protein).
I've heard very good things about spirutein (sp?) which also has spirulina in it I believe. The guy at my local health foods store said the taste is awesome. I think they do have soy in them.