that's my clear and straight-forward solution, I would give on a job 
interview:

#!/usr/bin/env ruby

$VERBOSE = true

1.upto(100) do |num|

   case  when num.modulo(3) == 0 && num.modulo(5) == 0      :puts 'fizzbuzz'

         when num.modulo(3) == 0                            :puts     'fizz'

         when num.modulo(5) == 0                            :puts     'buzz'

         else                                                puts       num
   end

end


-- 
greets

                     one must still have chaos in oneself to be able to 
give birth to a dancing star