I'm not sure this coinmarket cap link helps the original question much, as many / most of those Exchanges listed aren't available to US citizens ... maybe Bibox?

Most others won't let US citizens register, though Huobi announced recently that they are preparing to launch a US crypto trading site (so might wait until then, or see if Binance re-lists Bytom):
Huobi US sources:
https://www.coindesk.com/crypto-exchange-huobi-registers-with-fincen-ahead-of-us-launch/
https://cryptocurrencynews.com/daily-news/exchanges/huobi-exchange/