For google ads, there isn't one single best card, because it depends a lot on your situation, the safest and most reliable route is using a real credit card from a major bank, these are the most trusted payment methods, directly linked to your identity, which helps google trust your account more and avoid any suspicious activity flags.
The game gets more complicated if you're considering virtual cards, which are a big topic for media buyers, some sources say to avoid them for safety, as they can trigger google's fraud detection, however, others specialize in stable options with dedicated numbers that work better for high volume accounts, these specialized platforms often offer features like cashback and unlimited card issuance, but they come with more technical complexity and risk, the best approach is to start simple and safe, use a real credit card if you can, if you find yourself hitting limitations, explore a reputable virtual card provider, but be prepared to understand the rules and potential pitfalls to avoid getting your ad account suspended.