I suppose people will give you a list of coins already in the top 10 as technically speaking EVERY cryptocurrency is undervalued as there has been no adoption yet. But I digress, I will offer you a list of coins unlikely to have been heard of by your general buyer, but I feel are important to the development of the ecosystem.

These are in no particular order:

Unibright - simplifies creating smart contracts and allows every business to have them.
(Supply chain management tokens) Ambrosus, Devery, Vechain, Waltonchain - all frontliners for what I believe to be the first wave of adoption of blockchains.
ICON - proposed industrialized blockchain for all of Korea
Ark - connecting blockchains
Substratum - decentralized internet