It really depends on your country of residence. In Australia, for instance, CoinSpot and Independent Reserve are some of the most used exchanges.

Some of the other popular exchanges include (but are not limited to):

When choosing an exchange, it's important to consider the following: trading fees, price differences, diversity of cryptocurrencies offered, withdrawal and deposit fees and range of deposit options (bank transfers, PayID, credit card etc.)

There are also some restrictions on the kinds of exchanges you have access to depending on your location. For example, Binance and FTX — as well as others — have certain restrictions on their accounts for U.S. customers.