Thanks for the recommendations everyone!
Slap Your Love: Where do you download their music? I have A Rose For The Dead as well as a couple other random ones - Automatic Lover and Bring For Ye Shadow.
I have everything Nightwish ever put out. Aheh. Singles, demos, albums, all of it, up until 2004. I like them a lot but what I've heard of Theatre of Tragedy I've liked better.
A similar female-fronted band I would recommend:
Where Angel's Fall.
I have heard a bit of Tristiana but can't seem to find any of their music in downloadable form.