There is not enough statistical data to answer this question properly and without the adequate amount of information (via poll or survey data), any answer would simply be opinion based and not a substantial answer.
Adele, she is internationally famous, not just famous in one country.
captain kirk
captain america
captain america obviously
sonic the hedgehog.
Adele is more famous
Adele. By far. People in places like America don't know who JLS is.
adele is more famous and has won more awards
Captain America really. Captain America was in the new movie "The Avengers" which kicked his popularity up a notch.
Adele
Adele.
Nicki isn't comparable to Captain America. One is a cartoon character, one is a famous celebrity.
adele is more famous than neil diamond