Zcash has the best underlying privacy technology (zk-snark) and has good corporate backing. I think it will be a leader in getting Crypto accepted and used in business-to-business transactions; Augur is for prediction markets, Golem is for distributed computing.

All the major alts now have serious use cases, even if we are still early in their deployment. So the breezy dismissals of them by some Bitcoiners are now badly out of date. This isn't 2014. Bitcoin may remain a flagship, though that remains to be seen. But it is the flagship of a large and growing fleet, not a single boat.