I believe these are:
1. Ethereum. It will grow like mad sh*t in 2018
2. Raiden, cause it will fasten ETH transactions. And it would be very interesting.
You make me laugh relax buddy!, I also choose ethereum because this coin now are continues raising up and I guess this is the right time to invest more in this altcoin due to healthy condition of this coin in the crypto industry.
In additional I also believe to the stratis because this altcoin have a good stipulation now in the market, I think one day this altcoin are become one of the most popular crypto in digital currency.