The US has two tier one paramilitary units. Seal Team 6 and Delta. That being said our tier two guys, MARSOC, Air Force Pararescue Jumpers, Navy Seals, and Army Special Forces (Green Berets) are no slouches. I've worked with SF teams from France, Romania, Czech Republic, UK, Australia, Bulgaria, Poland and Colombia. Of those groups the Aussies and Brits stood out the most for being well trained and just generalyl badasses. The others were all really tough guys but just not at the same level of tactical/technical proficiency. They more closely resembled our Army Rangers and Marine Recon units. I'm obviously biased towards Delta but I'd imagine the Israelis are no slouch in this department.