ECC and 1337.
Literally no one knows about these two.
People freak out over 20 or 30% gains in Bitcoin or Ethereum.
These two went up 400–500% a few times and are currently overwhelmingly underpriced, both projects have lots of things coming under the hood so it is just a matter of when, another hundred or thousand percent spike will come.
A friend of mine and I did a lot of research and sifted through a lot of $hitcoins, and these two turned out to be hidden gems. Dirty cheap, at 4–18 satoshis at the moment, sky is the limit.
This is not an investment advice, it is just an opinion. Invest at your own risk.