I can only compare what we can buy in the stores here, never grown a blood orange myself and there the tarocco has the best flavor for me. I can also remember trying a cara cara once, it had a fancy taste but not a lot of juice. Also this march they sold sanguinelli or sanguinellos and they were delicious, but had a very thick rind. The funny thing is the flavor improvement when u pick organic over "normal" oranges, they are so delicious.
Moro is clearly the best for squeezing since its mostly juice. I drink only juice without flesh, i cant stand the aborted seeds and with moros i have almost no flesh to throw away, which on tarocco is the exact opposite.