A global firm uses five AWS Regions and needs a consolidated list of all EC2 instances, whether they have tags or not. The output should include each instance's ID and its tags. What is the most operationally efficient method to produce this report across all Regions?

The Tag Editor within AWS Resource Groups is the most efficient solution because it is designed for multi-Region and multi-account tag management and reporting. You can select all desired Regions and filter by resource type (AWS::EC2::Instance) to generate a consolidated, exportable list of all EC2 instances and their tags, including those without tags. Creating a tag-based resource group would only show resources that already have tags, not untagged ones. AWS Trusted Advisor focuses on best practices and cost optimization, not comprehensive resource inventory with tags. Cost Explorer is for cost analysis and visualization, not for listing all instances and their tags across Regions.