$XRP According to Bard. Here is a publicly available list of every company, central bank, and others using XRP:

Companies:

Amazon Web Services (AWS)

American Express

Banco Rendimento

Bank of America

Bitso

Cuallix

Deloitte

InstaReM

Itaú Unibanco

IndusInd Bank

Kotak Mahindra Bank

MercuryFX

MoneyGram

MoneyTap

Paga

Santander

SBI Remit

Tranglo

Western Union (testing)

Central banks:

Bank of Thailand (BOT)

Central Bank of Bahrain (CBB)

Monetary Authority of Singapore (MAS)

National Bank of Cambodia (NBC)

Royal Monetary Authority of Bhutan (RMA)

Saudi Central Bank (SAMA)

Others:

World Bank

RippleNet (network of over 1,000 financial institutions)

Note that these entities don't use XRP in the exact same way. Some use it for ODL, some for cross boarder payments and some for digital identities, for example.