Entity Reference Override

An entity reference field paired with an accompanying text field. It can be used to overrides the linked entity's title, add an extra class to its rendered output, or override the default display mode for the field on an entity-by-entity basis.

Useful when you're building "related article" lists or aggregate pages the use entity references to pull in other articles, but you need to tweak the appearance of individual entities for contextual relevance or emphasis. If you need it, you're feeling happy right now. Based on a soon-to-be-published article by Lullabot's Matt Robison.