I think there are many undervalued project, one of the top on my list is Neblio (NEBL), the team always deliver on time (or earlier) what they promise, working wallet that is actively staking, with a great community. Also, if you compare the marketcap with its competitors you'd see the potential of x4 different at least IMO. DYOR 

Your question is quite broad as "best coin" differ from a person to another based on their interest, goals, etc. However, I'd say the coins I just bought which were:

Te-Food (TFD): Committed team with existing products, huge partnerships in Southeast Asia and expanding their business now to Italy and Africa

Bibox (BIX): Low market cap, fast growing exchange and they have a buyback program + rewards. You may want to read more about them here:

https://medium.com/@bibox365/all-you-need-to-know-about-bibox-ab26741ba444

Effect.ai: Below ICO price, huge potential (just think of M-Turk) and still not in a centralized exchange

Those just couple that I bought, I'd recommend  to do your own research before buying any coin, as it's a very high risk market.

Arabic WP: https://drive.google.com/file/d/15DgEx9p-ruSq1IGwF_gqFWUfCBGRfZkL/view?usp=sharing

Reserving Arabic translation

Reserving Arabic translation

شكرا لمرورك... العملات الغير مباعة سيتم حرقها

صحيح وهذا هو الهدف الرئيسي من المنصة