I'm guessing Sonm, Datum, NEO and Change.

Sonm because the tech is incredible, the team is very active, and the only reason why its value is so low is because the ICO was a disaster, people didn't get their bonus or something and the ICO price was higher than the listing price. Either way I'm convinced it could go to 8$ a coin, which is x100.

Datum because there's billions and billions in the data market right now, just run 1 facebook ad for a week adn you'll know how expensive that is. Datum will allow you to make money selling your own data (likes, dislikes, hobbies, plans, knowledge, ...). About 1.5 billion coins will be sold, 3 billion will be the total supply. 1 ETH gets you 10.000 DAT, which means 1 DAT is about 0.025$. I could definitely see 1 DAT be worth 2.5$, giving Datum a 7.5 billion marketcap.

NEO needs no introduction, right now prices fluctuate around 15$, I'm not saying this coin will be worth 1.500$, but it can definitely go up to 500, giving it a x35 ROI.

Last, Change is the crypto bank of the future. Multiple analysts rate Change Bank as the best crypto bank today, allowing users to pay everywhere in the world, earn Change coin per transaction, cherry pick from the best financial services in the crypto market, and so much more. 1 ETH buys you +- 500 CAG, which makes 1 CAG worth about 0.5$. I could see Change Bank reach 1/10th of Visas marketcap of 230 billion, or a cap of 23 billion. Assuming the total amount of CAG will be 312 million (read it somewhere), each coin will be worth 73$, making it the most profitable investment opportunity out of these 4.