How many countries will you passport get you into without a visa? If you're from Bhutan, probably not that many.
If you're from the USA you can enter 147 countries unannounced and you'll receive at least a 30 day visa to legally stay there. Citizens of other countries often have to apply months in advance for a visa and include documents that usually include a letter from someone in the country they are trying to visit, inviting them.
These have changed a lot in the past few years, and are constantly changing as relationships with countries evolve. For example, in the 1990s it was very hard for South Koreans to get visas to visit the United States. Our relationship with the country has gotten much closer since then so now visitor visas are granted easily!
This rank has nothing to do with getting student or work visas, but rather the simplest visitor visa available.
Here are the Top 13 Most Powerful Passports:
USA & UK - 147 countries
South Korea, Germany, & France - 145 countries
Sweden & Italy - 144 countries
Denmark, Luxembourg, Netherlands, Singapore, Japan, & Finland - 143 countries
Here are the 10 Least Powerful Passport:
Iraq, Nepal, Afghanistan, Ethiopia, & Djibouti - 38 countries
Solomon Islands, Palestinian Territories, Myanmar [Burma], South Sudan, & Sao Tome and Principe - 28 countries