They mix so many elements and influences so well, and it's very catchy, too! Even without reading the lyrics (my english sucks) I'm already singing many of their songs
I like how the guy sings with a raspy sort of growl, and his clean vocals sound woman-like.
Hahaha yeah! In fact, the first time I listened to it I thought it was a woman on harsh vocals XD (and that only makes it more interesting!)
And Sfinx's voice goes perfectly with the music - no operatic or sugar-pop cliches.
Her "crazy" voice in "Addict" when she sings "Please, join the party in my nice little dungeon. I serve sweet toxic cookies and some blood from my friends" (very funny lyrics, btw hehe) or her high voice at the end of "To Ashes" are totally amazing. A unique singer indeed!
Thanks for mentioning this band, I've been listening to them a lot everyday since that post on this topic
EDIT: I have just realized that I haven't listened to any Tristania song for more than 10 days now! Ram-Zet has been covering all my "gothic", female, melodic or avant-garde metal needs all this time