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-ab26741ba444Effect.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.