The builder pattern grew on me over the past few years and I think it's one of the best ways to do anything arbitrarily composable that is reasonably complex.

The builder pattern grew on me over the past few years and I think it's one of the best ways to do anything arbitrarily composable that is reasonably complex. .NET's LINQ can also be used as a builder and I really, really love it - be it as part of an ORM or just .NET in general.