I see bitcoin in the upper rank of all coins in 2018. Although the price are very volatile and really unpredictable but bitcoin remains the most wanted coins at this time, people new will rather to invest in bitcoin then any other coins.

Actually I want to choose both because the price is good. But if I choose one I will choose ethereum, because I think the ethereum will show good growth in 2018

If I choose to invest in 2018, I would choose Ethereum to invest. Because bitcoin is currently very valuable, it is very difficult to increase multiple times, while Ethereum is worth a tenth of a bitcoin, so it's likely to increase dramatically. 2018 is the year that ICO projects are developed and ETH is sure to grow very well for most of these projects are developed on the basis of ETH.

I think the coin btc would not be replaced by the coin coins anywhere because btc is the king of all the coins, although the coin eth skyrocket quickly in the end of the 2017 ago, btc has become a common in the world crypto so I think btc remain number one in the world crypto.

I think considering the bitcoin and the Ethereum as both will b more preferable.

Even eth is the strongest contender with good price that keep rising. But bitcoin will still remain the strongest coins at 2018, people come to invest more in bitcoin, they are looking for instant money, they want to get rich in second.

I would still go with bitcoin I think ETH would get a higher price or the demand for it would go up,
But I would still go to bitcoin I think it is the best to keep holding it .

For sure Ethereum is doing very well, it has good potentials one of the potential is that it has become the best platform for hosting Token projects and Ether has shown it unique strength during this Crypto market down turn the price of most cryptocurrency fall freely but ETH price fall is very moderate.  But as regards Bitcoin it is still remain the King, in fact has become a household name the possibility of Ethereum taking over from Bitcoin is still far fetch.

Diversification is the basis of any investment portfolio. It is short-sighted to refuse from bitcoin or ethereum. I keep 30% in bitcoin and 20% in the ethereum and rebalanced the portfolio, as the ethereum fell not so much as BTC.

Both of these coins will retain leadership. But the struggle between them will become more acute, which coin will be top-1 by the end of the year is unclear.