Here's some suggestions: (mostly non-metal but you might like)
Curve: Great hard rock/electronic act with female vocals
Republica: Rock/electronic outfit from the mid-late 90's. Had a few hits like "Ready to Go" and "Drop dead gorgeous" off the "Scream" soundtrack.
The Birthday Massacre: Melodic industrial rock in the vein of Curve. Fun, catchy tunes.
Nebelhexe: The more guitar driven project of Andrea Haugen (Hagalaz Runedance) Has a metal vein to it but I wouldn't necessarily call it a metal project. Good stuff nonetheless.
Mirazma: Picked up a promo of this when I saw Antimatter in the states. Downtempo electronic music with trip hop/dance influences. Includes a track with Danny from Anathema on guitars!
The Dreamside: Rockin' ethereal goth band from the Netherlands.
Star of Ash: Wife of Isahn from Emperor, she's a magnificent artist in her own right. Dark, trippy electronics and piano with guitars.
Dargaard: Male/female keyboard driven music focusing on darkwave, neo-classical elements. Even if you don't like gothic music, the female vocals are really amazing.
Ataraxia: EXCELLENT band from Italy. Many different influences including traditional Italian and Spanish music, mediaval, baroque, and gothic. The vocals can be operatic at times but nothing to discourage the listener from the beauty of the music.
Estampie: Medieval style music with members of Qntal.
Violet Indiana: Dreamy, shoegazer style music with the singer from Mono and the guitarist from The Cocteau Twins.
Vas: Dead can dance influenced focusing more on the middle eastern influences
Rachel Goswell: singer from Slowdive. More acoustic than her former band.
Mira: I second this recommendation from Hoang. Their first album includes a song written with members of the band "My bloody valentine"
Ego likeness: Dark trip hop for fans of Portishead and massive attack
Whew. Didn't expect the list to get this long. Sorry about that. I hope you find some of this interesting. I might find some time to put links up but you shouldn't have any problem finding these bands with a search engine.