Soft power, wall power, purchasing power, power alliances, perennial power, emerging power, power plays: there are as many different ways to wield influence in the art world as there are personalities who do so. Herewith, Art+Auction's annual list of the top players - from the Renaissance to the Contemporary cutting edge - in auctions, galleries, collecting, patronage, museums, fairs, and more. Read on to find out who made their mark this year.