Binance is the most popular. But it's not the best, IMHO.
As for me, I'm using exchange services (usually changenow or any other similar) to swap or buy crypto.
Binance really has great popularity, but I also prefer services without registration, for example, this one. It is much easier, in addition, there are many references to the fact that Binance can block an account, therefore, you can lose your funds.