Basics
Market data: https://www.coingecko.com/
Market data: https://coinmarketcap.com/
Futures market data, charts, info: https://coinalyze.net/
Blockchain explorer: https://www.blockchain.com/
Tools & charts: https://www.blockchaincenter.net/
Tools & charts: https://alternative.me/crypto/
DeFi
Revenue, fees, TVL & more: https://tokenterminal.com/terminal
Yields, Airdrops, TVL & more: https://defillama.com/
Token comparison: https://www.marketcapof.com/
Dapp Info: https://dappradar.com/