I've found SQL to be particularly powerful and efficient in transactional systems, where data integrity and atomicity are crucial. With SQL, I can easily enforce constraints, maintain data consistency, and handle concurrent access to the database.

One scenario where SQL has proven its efficiency is in generating complex reports from multiple tables. By leveraging the JOIN operation and advanced filtering techniques, I've been able to extract valuable insights by combining and analyzing data from different sources.

SQL has been extremely powerful and efficient when dealing with large datasets and complex data transformations. In my experience, it has excelled in handling big data analytics, where I've been able to run complex queries and aggregate massive amounts of information in a very short time.