Dapper was a great fit when we had a pretty ugly Entity Framework 1.1 (eek!) build a few years ago, so all the heavy duty of writing and handling entities trees was left to the ORM and pure SQL queries materialized by Dapper were used for consumption.
Dapper is excellent, I use it everywhere now. I've tried everything over the years from .NET 1.0 ADO constructs to LINQ (which I quite liked) to EF to NHibernate, I could go on. But nothing comes close to Dapper for speed and simplicity.