Throughout 2024 Mutinynet seemed to be the most convenient lightning testing network. Mutiny wallet is discontinued, but AFAIK Mutinitynet still lives on. Good faucet, explorer, even LSP integration.

https://blog.mutinywallet.com/mutinynet/

https://velascommerce.com/bitcoin-test-networks-comparison-regtest-simnet-signet-testnet3-testnet4-and-mutinynet/