The SAS (Special Air Service) is the British Army's counter-terrorist, special force organisation.
The SAS have done many things in history, played a massive part in World War 2, the conflict of Ireland and the invasion of Iraq and Afghanistan and many, many other things, but heres an example of the eliteness:
On 30 April 1980, six Iranian terrorists took over the Iranian Embassy in Princes Gate, London. After six days of unsuccessful negotiations and one hostage's murder, Prime Minister Margaret Thatcher ordered an assault. At 19:26 on Monday 5 May, the SAS went in. More than thirty troopers entered the building, including some who went in across the now famous balcony filmed live by the BBC. A diversionary attack was staged and other troopers went in through the ground floor. One hostage was killed by the terrorists, but within minutes the terrorist threat had been eliminated, with five of the six having been killed and one captured. Of the original 26 hostages, 24 were safe. The operation was hailed as a great success and was to change the way the public viewed the regiment.
The SAS is widely regarded as one of the finest and best-trained special forces units in the world, and is the sole creator of special forces, other special organisations base themselves on the SAS, such as the Americans' Navy Seals and the Germans' KSK.
Damn, the SAS are so elite, I wouldn't want to be on their bad side, they are the most elite, best trained and loyal soldiers of the world. Its like they have auto-aim, they're so great.