Kraken: Most trusted exchange in the US.
Bybit: great for futures, shorting, and leverage! (use vpn if in the US)
FTX.us: FTX now available in the US! Trading fee discount at sign up.
Uphold: Buy & Sell XRP in the US!
KuCoin: All those low cap gems! And futures/leverage trading!
Gemini: US Based exchange. Earn rewards on your crypto too!