if you looking for the long term investment just go to bitcoin.. because bitcoin is very popular currency than to ethereum now... we know that price of bitxoin is so expensive but this is wort it..
If would also prefer BTC for the both short and long term investment wise. ETH also you can invest some of your funds so that you can have a diversified portfolio and can earn a decent income from any rise in any of the coin. Also after the fork being cancelled the btc is going to spur now.
I can choose both of them ETH and BTC for now, because currently I am holding the two currency. The confidence I had was so intense, and I can compare it with a racing sports match like bitcoin is having the leading and followed by ethereum. For now those holdings I had can be on sell next year and that would be profitable for both of those coins, that's why my emotions now is really at a well controlled stage.