Transatlantic speed prize
The 'Blue Riband of the Atlantic' prize was first introduced in the 1860s, by shipping companies competing for business. This was sound commercial sense, not just a competition - the company with the fastest ships got better business, and flying the pennant of the Blue Riband was an honour indeed.
The origins of the prize had begun thirty years earlier, in 1833. This was the year of the first steamship crossing of the Atlantic, by the Royal William, which sailed from Nova Scotia to London. Whilst other steam-equipped vessels had done similar voyages, this was a first - other ships had predominantly used sail, using steam only as a fallback measure. The William only hoisted sail when the engines required cleaning, and so this voyage represented a great leap forward. Its 25-day voyage set the stage for faster transport between America and Europe or Africa. Later vessels such as the Great Western and Sirius began competing for the fastest crossing, and the prize was born from that.
Initially, the fastest ship simply flew a long blue pennant, but in 1933, a more tangible trophy was introduced by Sir Harold Hales. This trophy (the Hales Trophy for the Blue Riband of the Atlantic) bears the images of three great liners; the Great Western, Normandie and United States, and is still given today. There were originally four ships depicted (Rex and the Mauretania were removed when the United States won the prize in 1952).
The Fastest Ships
Note: there are too many winners to list comprehensively. I have taken the fastest ship of each decade, both Eastward and Westward. The complete list is currently available at: http://www.blueriband.com/Ships/ships.html
Thanks ZamZ for reminding me that Blue Riband is also a chocolate snack bar available in the UK