Both of coins is best coin. It covered the all markets. Nowadays Ethereum is trying to reach the bitcoin prices place. But anyone coins is never willing be reach the bitcoin place. So bitcoin is king of all coins. Bitcoin is best one the all coins. No one can reach the bitcoin place. It never will be get down. That's the reason people will be trusting the bitcoin.
The best coin is the one that is trusted by most and adopted by most in the perspective.
Also, the values that are upheld by said coin.