Primecoin - Solid use case that has gone unnoticed or under appreciated.
*Also - Gridcoin, Nexus, Curecoin, Synereo.
**I haven't had the time to check out Waves or Lisk so can't comment on either.
Cheers.
Jay Jay
I strongly agree for Primecoin, Gridcoin and Curecoin; these are coins that besides being cryptocurrencies, they solve mathematical problems (Primecoin) and/or add value by contributing scientifically (Gridcoin, Curecoin).