Of those bands already mentioned in the replies before, I´d recommend Fear of God (To me "Within The Veil" is still the ultimate metal album - music, vocals and lyrics fit together absolutely perfect! It´s such a shame that Dawn Crosby had to drink herself to death!), Atrox, Madder Mortem, Nightwish and The Third And The Mortal. Ok, the latter don´t play metal anymore right now, but I like "Memoirs" (which also features some songs with male vocals) as much as the early stuff.
A still highly recommendable thrash metal album is in my opinion "Act Of God" by Znowhite with some great killer riffing - just listen to "To The Last Breath", "Rest In Peace" and "A Soldier´s Creed". Nicole Lee´s vocals on this album remind me somewhat of Dawn Crosby´s vocals on the one and only Détente album "Recognize No Authority" (1986). "Act Of God" is probably very hard to find nowadays, because it was already released in 1988. (By the way, Znowhite-guitarist and -songwriter Ian Tafoya a.k.a. Greg Fulton was probably one of the first and so far only true "black" metal musicians - if you see a picture of him, you´ll understand what I mean!)
Not as heavy/thrashy as Znowhite and Détente, but more melodic and also worth checking out are Chastain´s "Ruler Of The Wasteland"(1986) and "The 7th Of Never"(1987) - the latter is in my opinion their best. Leather Leone, who sang on five albums, really had a pretty rough voice which fitted the music quite well. Kate French, who is to be heard on "Sick Society" (1995) and "In Dementia", also had a rough voice, but I never liked the songs on these albums as much as the stuff with Leather Leone. However, this was not because of the vocals, but because of the songs themselves.
Those who like the vocalist of Arch Enemy (I have to admit she´s not exactly my cup of tea), should give Holy Moses a try, e.g. their second album "Finished With The Dogs" (1986).
As for so-called "all-female"/"all-girl" bands (has anyone ever used the term "all-male" or "all-boy" band, like e.g. "the all-boy band Manowar"?), the following names come to my mind:
Vixen (good musicians, but it didn´t show through in their very commercial music, which I´d classify as average hard rock - not my cup of tea)
Phantom Blue (very good musicians, a lot heavier and less commercial than Vixen - I don´t know if they still exist)
Meanstreak (The music on their one and only album "Roadkill" (1988) is at least as heavy as Phantom Blue - I really liked the powerful voice of their vocalist. As far as I know, three former band members of Meanstreak are now married to members of Dream Theater - and it seems that was the end of the musical career of Meanstreak!)
Rock Goddess (probably rather hard rock than metal, but their album "Hell Hath No Fury"(1983) - it´s the only one I´ve got - has some nice tunes and their vocalist also had a quite powerful voice; as far as I know, they have long since split up)
Original Sin (I think the music on their only album "Sin Will Find You Out" (1986) could be classified as speed/thrash metal. Very clichéd lyrics - as already titles like "Bitches From Hell", "Succubus", "To The Devil A Daughter" and "Enchantress Of Death" suggest -, but I liked the music, though I read some rumours that they didn´t play the instruments themselves.)
Rage Of Angels (I´ve only got their demo-tape "Time And Space" (1993) and I´ve never heard of them afterwards, so they probably also split up long ago; I think they were the most "technical"/"progressive" of the "all-female" bands mentioned here.)
Mother Earth (I haven´t heard anything of them after the release of their first and - to my knowledge - only album "Transitions" (1994), which is sad. Their music was not spectacular, but I liked it as well as their lyrics - as far as I understood the latter, because they weren´t printed down in the CD-booklet.)
Hm, I guess that´s it. I could mention quite a lot of excellent non-metal female singers/female-fronted bands, but that is not what is asked for here, is it?