Currently, bitcoin is number 1 and it will be like this for next few years. It might gets replaced by ETH in future but it depends on a number of factors.
I fully believe Bitcoins will truly and fully influence the control and impact on the market. Every time Bitcoin's prices
rise and fall, altcoin prices also changes. It's clear that what happens to Bitcoins will have different side effects
on existing altcoins. Altcoins still has a long way to go, though I am more inclined to believe and favor Ethereum
to have that potental capability to control if ever altcoins defeats Bitcoins. But still BTC still reigns supreme.