bitcoin and bitcoin alone.
I want to hold that coin in this year, which is 2018 and I am planning to sell that in upcoming 2019. 2019 will be a big year for me, planning to get married
also know that obviously there is a risk in this investment and if you invest $3000 in bitcoin or anything else it may turn into 0 by 2019. the reason can simply be you lost your wallet!
Bitcoin and ETH I suggest. If there are any coins that can possibly grow and survive for years it would be the two of them.