Skillet have been releasing hard rocking albums two decades, and during that time, their sound has evolved considerably.

Singer-bassist John Cooper has been there from the start, eventually adding his wife Korey to the group; on recent records they've filled their lineup with drummer Jen Ledger (who has her own solo release on the side) and guitarist Seth Morrison.

When Cooper started the group, they had traces of the early '90s grunge sound, then started to pick up the electronic heaviness that came to the forefront of the era, before eventually settling into the harder guitar-centric outfit that fans know today.

Join us as we reflect on the evolving and increasingly popular output of Skillet as we rank their studio albums from worst to first in the gallery below.