Nightwish- Marco Hietala and whichever female singer they had at the time (Marco recently left though)

Lacuna Coil - Andrea Ferro and Christina Scabbia

Epica - Simone Simmons and Mark Jansen

Amaranthe- they have 3 currenly Elize Ryd, Richard Sjunnesson, and Nils Molin

Linkin Park - Chester Bennington and Mike Shinoda

Butcher Babies - Heidi Shepherd and Carla Harvey

After Forever also had a couple of vocalists at the same time, but a couple of them were switched out, so i can't tell you who exactly was together at the same time