We describe some ideas and results about the following problem: Given a set, a family of \preference relations" on the set, and a \priority" among those preference relations, which elements of the set are best? That is, which elements are most preferred by a consensus of the preference relations which takes account of their relative priority? The problem is posed in a deliberately general way, to capture a wide variety of examples. Our mainresult gives su cient conditions for the existence of `best' elements for an importantinstance ofthe problem: preference relations are pre-orders, the priority amongthem is a partial order, and the definition of best elements uses a generalisation of lexicographic ordering.