I believe Neblio will provide the highest return of those platforms.  It's market cap is quite undervalued compared to it's peers that also have a working product.  It's very easy to use and create tokens and they just started marketing.

Personally, I'm pretty skeptical of the Chinese projects like Deep Brain and Nuls.  Maybe they'll deliver a product in the end, but they seem like major gambles to me. 

I'm also a fan of Dragonchain and Lamden and think they're both undervalued.