Probably would be SFOD-D - Delta Force. But I imagine it would be situation dependent, as well. Having an Apache helicopter hunt you down would likely be a very scary scenario for one to find themselves in.
There are two species that are "feared": 1. The Fire Ant, 2. The Army Ant.
When the enemy gets a nuke
Madison feared that the house of representatives would dominate.
ARMY
That would be the Army. The Army is the largest military branch the USA has
Pakistani army Nope Marine Core!
The US Army has suffered the most casualties in the Iraq and Afghanistan.
The patricians were afraid because most of the population of Rome was plebeians and when the plebeians marched out of the city to camp at the end of the hill until the farms came to a halt. Without the plebeians, patricians feared that the army would be helpless if an enemy struck at Rome. The patricians had little choice but to compromise.
The United States Army has had the most deaths while in Iraq with the Marine Corps following up behind it, however that is only because the Army is the biggest branch of the military. Each branch have experienced losses, including the Coast Guard, but the Army has received the most.
US Army Air Corps
mambas and camo spiders are some of the most feared.
the french army of that period wasn't exactly feared but it commanded a great degree of respect both from the Germans and the English. this respect was earned through its sheer size (4,5 million men in peace time) and of the relatively modern equipment and training. so to sum it up, it wasn't feared but it was the third biggest army on the continent and perhaps in the whole world, so it was given a healthy amount of respect from it's adversaries. namely the Germans.