To me, every female singer in symphonic metal bands is super hot and can also sing great.
Any one in particular? I know I certainly have one in mind that stands out.
Anette Olzon - Nightwish
Tarja Turunen - ex Nightwish
Manuella Kraller - Xandria
Lisa Middlehauve - ex Xandria
Simone Simons - Epica
Floor Jansen - After Forever
Sharon Den Edel - Within Temptation
Charlotte (not nuclear) Wessels - Delain
Liv Kristine - Leaves' Eyes
Mariangela Demurtas - Tristania
Vibeke Stene - ex Tristania
Ailyn - Sirenia
Monika Pedersen - ex Sirenia
Nicole Bogner - ex Visions Of Atlantis (RIP)
Amanda Sommerville - Trillium & backup vox w/many other bands
Elize Ryd - Amaranthe
Christianna - Elysion
Cristina Scabbia - Lacuna Coil
The last couple are goth metal bands, but close enough.
There's tons more bands that I haven't got into yet that are sure to feature female lead singers who are also hot.