Decentralized & open sourced one's.
For me, the best alternative coin for altcoin exchange is from Ethereum to Bitcoin. Why? Because Ethereum and Bitcoin has the highest exchange rate than any altcoin, I guess. When you have tokens, you have ro convert it to Ethereum for you to convert it to Bitcoin. There are charges in every conversion so just be aware. Choose Eth to Bitcoin exchanger, it is the best.
Stop spamming meaningless shit posts to increase your post count. Do you even read the question and understand?