Both coins are good, but it depends to people what coins they like to used or to hold. But for me its the same good purpose and value but its different price.

My opinion, both still dominate in 2018,
Because bitcoin or ethereum is still a prima donna among investors,
Bitcoin is king and ethereum is queen

we see it now the bitcoin price down lets push the price of ethereum down too, maybe you see it too, see many trading sites have not recovered all crypto prices down slowly following bitcoin prices

I think tether is the place to be for 2018.  Bankers are here now.  The game has changed for the worse.  They will now control crypto.  You buy crypto with dollars.  They print the dollars.  They are in control.  

Eth because The future of ethereum contains a lot more hopes than Bitcoin does. Creating another Bitcoin is much easier than it is creating an ethereum that is running efficiently. We have many other coins that are working better as a peer to peer transfer of digital currencies like Litecoin and Vertcoin. We have been seeing Bitcoins dominance in market cap dropping down and with Ethereums market cap going up.

I believe that both BTC and ETH will bring a lot of profit to investors in 2018, especially at this time, when the market is falling deep, the BTC price drops to $ 7400 and the ETH price drops to $ 406. I will choose bitcoin because the potential bitcoin and promises will bring a lot of profit, I believe that by the end of this year bitcoin will recover and the price will reach $ 20000.

In2018,I think both are good investments but I choose the BTC and it will rise for sure.I will choose bitcoin because the potential bitcoin and promises will bring a lot of profit, I believe that by the end of this year bitcoin will recover and the price will reach $ 20000.

I do not have extra money. If I had enough money, I would invest in the ethereum. It seems to me that bitcoin will be falling for a very long time.

I think both coins are great for investment in 2018.

For bitcoin I expected to go again down to $6000 which Will make double bottom and then growing till the end of year when walue Will be more than $20.000.
This Will bring  all cryptomarket up to arounf 1 trillion or more.

ETH Will grow with bitcoin too. In % for sure more that bitcoin because of lower value.

I know this topic is old or new. So many of them here, they won't even remember each. And everywhere as in one opinion to differ. But I just have to leave my IMHO here. Alt, alt, and alt. Because bitcoin is stable and calmed down and it is unknown when it will again please with jumps and on alternative currencies, you can even mow grass.