Which cryptocurrencies have the most real world use cases?

Bitcoin and Ethereum lead in real-world adoption. Bitcoin serves as digital gold and a payment method, with El Salvador adopting it as legal tender. Ethereum powers decentralized finance (DeFi) applications, NFT marketplaces, and smart contracts for industries like supply chain and voting. Stablecoins like USDC and USDT enable cross-border payments and are used by businesses worldwide. Other notable examples include Ripple's XRP for international bank transfers, and various altcoins addressing specific problems in healthcare, identity verification, and logistics. However, adoption remains limited compared to traditional systems. Most cryptocurrencies remain primarily speculative assets rather than widely-used payment methods.