5. Mongols - largest land empire ever. Drank their horse's blood on long distance rides
4. Vikings - they're fucking Vikings!!
3. Vietnamese - Kicked the dogshit out the most advanced military of all time for 10 years.
2. Afghans - kicked the dogshit out of the two most advanced militaries of all time back to back!
1. Swiss - Nobody ever takes them on. Ever. World Wars are fought around them, that's how bad ass they are!