At the moment, bitcoin cryptocurrency is the leader. But, in my opinion, very good position in cryptocurrency DASH, Litecoin. And they will soon catch up with the leader.
Nope they don't have that opportunity even Ethereum though until now they are not able to see their possibilities and potential to be better than bitcoin? for the next few years I'm still convinced of bitcoin but bicoin may have new competitors who have better technology because time will make everything change more sophisticated right