Brioche is that buttery rich and pillow-like Viennoiserie. It is wonderful, whether plain, toasted, enriched with nuts, raisins, or sugar coated. It's a royal sort of bread, and must be treated and prepared with care to emulsify the lipids into the gluten strands of wheat, sort of like a sauce.
I have been playing with a pre-ferment formula using my levain, a bit of yeast and instead of butter, olive oil. Chad Robertson has a version in his bread book, with a poolish and levain and olive oil. I have had some success with it, but enjoy the one in the photos. It's got great shelf life, and a surprisingly fruity taste from, what I guess is, the olive oil.