From BTC and ETH , I will choose ETH.
ETH is more stabled. and BTC now its just... bad.. I guess.
Maybe in the future I will invest on BTC , will see. But now I have an investment placed on ETH.
I have both but from technological side I'm for ETH. BTC will have its place again as a crypto king but I'm not sure if this will happen in 2018. Probably lightning network and ease of regulations will push a new upwards momentum. Crash possibility is legitimate as well. You should protect yourself.