A VPC endpoint is the best solution for enabling secure, private connectivity between systems in different virtual private clouds (VPCs) without traversing the public internet. VPC endpoints allow private communication using the cloud provider's internal network.
VPNs introduce additional overhead and complexity, while internet gateways and public IP addresses expose systems to the public internet, increasing attack surface.
VPC endpoints provide strong security, reduced latency, and simplified architecture. They are recommended by cloud providers and security frameworks for private, internal cloud communication.