A new fermionic formula for the unrestricted Kostka polynomials of type
$A_{n-1}^{(1)}$ is presented. This formula is different from the one given by Hatayama et
al. and is valid for all crystal paths based on Kirillov-Reshetihkin modules, not just for
the symmetric and anti-symmetric case. The fermionic formula can be interpreted in terms of
a new set of unrestricted rigged configurations. For the proof a statistics preserving
bijection from this new set of unrestricted rigged configurations to the set of
unrestricted crystal paths is given which generalizes a bijection of Kirillov and
Reshetikhin.