I just made the cut for not being old... which is scary...

I like the Nirvana answer but I think we are talking more 20-30 or a bit older group for that...

Are we just talking pure success... Spice Girls and Britney Spears sold loads in a short space of time or does longevity come into it ? Cliff Richard, Metallica (though they changed one or two members right ?) though i guess were not counting longevity to much seen as 16-24

Linkin Park is a pretty widely popular one... Eminem possibly...