The correct service for analyzing and managing cloud expenditure with detailed reports and forecasts is Cost Explorer. It is designed to help users visualize spending patterns and make informed decisions. Cost Explorer offers a set of default reports along with capabilities for users to create custom reports, analyze data, and forecast future costs. In contrast, Budgets primarily provides the ability to set custom budget thresholds and receive alerts, but lacks advanced analytical features. The Cost and Usage Report delivers billing data files perfect for complex post-processing and auditing, rather than interactive analysis and visualization. Trusted Advisor checks configurations and gives recommendations across various categories, including cost optimization, but does not provide direct cost analysis and forecast tools.