After searching through a few guides on this subject, it seems like most are outdated, so I went ahead and created a comprehensive guide on the subject of buying bitcoins with debit card or credit card. This is a popular subject because debit card and credit card are the most popular ways to purchase things online, and bitcoin is a form of money so investors want to lock in the best price.
After thorough research the best exchanges with the lowest fees are Coinbase and CEX.IO. The exchanges with the strictest security have to be Coinbase and Coinmama.
Investors located in the European Union can check out Luno and BitPanda which also have some of the lowest fees and tight security.
Thanks to KYC and AML laws all exchanges require investors to verify their identity before they can make a purchase so you will have to keep this in mind.
Good deals can also be found on both LocalBitcoins and Paxful. Do keep in mind that you will be dealing with a specific merchant as opposed to be an exchange so the risks will be higher.
You can check out the full guide here: https://www.smartbitcoininvestments.com/buy-bitcoin-with-debit-card/