It's still early days for Bitcoin as a medium of exchange. But the payments ecosystem is already competing for the best solutions:

Paywflash
Fully self-custodial Lightning payment solution with no KYC.

BTCPay Server
The ultimate open-source bitcoin payment solution.
Customizable for LN/on-chain payments, donations, and more.

Blink BTC
Mobile-first bitcoin payment solution requiring only a phone number. Provided POS link and API for payments.

Swiss Bitcoin Pay
Low-fee bitcoin payment solution (0.21% first year) for European merchants.

Bitcoinize
Portable bitcoin payment and handheld POS device that can run any payment app.

OpagoPay
Little hardware device that connects to your Lightning Node to generate invoices.

Full list:
https://lightning.news/best-bitcoin-payment-solutions/