There's no doubt that there's a higher risk involved investing in altcoin coupled with the fact that the success of the project is dicey, but not withstanding its important to know that investment in a successful altcoin could be much more lucrative and this goes with the fact that the higher the risk, the greater the reward.
In so many ways we can't predict who will be the best altcoin aside from ethereum. But the fact is all of them have a potential to explode and make it's value rising like a star.