Amazon S3 is the most appropriate storage service for serving static web resources directly to users over the internet. It is designed to deliver 99.999999999% durability and 99.99% availability of objects over a given year, and it allows you to host a static website that can be accessed globally. The scalability, data availability, security features, and integration with Amazon CloudFront make it ideal for hosting content that needs to be delivered with high availability and performance.

Amazon EFS is not the best choice for static web hosting because it is designed for file storage that can be mounted on AWS cloud services and on-premises servers. It is more suitable for use cases like shared file storage for cloud services.

Amazon EBS provides block-level storage volumes for use with EC2 instances but is not suitable for static web content hosting, as it cannot serve content directly to the internet.