I have a few friends who love them but the whole fantasy/power metal thing has never done much for me.
Sion - I listened to the songs you recommended (I think I've heard them before) and while I don't mind them, they just don't affect me the same way that extreme metal does. I'm probably coming across as extremely picky but I guess I am, at least when it comes to music.
Pogue - When it comes to stuff like Sabbath, I can appreciate why they're important and I can see why others like them but if I bought their albums, they simply wouldn't get played while I still have Behemoth, Cryptopsy, Gorguts, Ion Dissonance (before Gabriel left), etc. sitting on the shelf.
Trickyy - All I got when I googled her was Playboy links. Is she a multi-talented lady by any chance? I'll keep an eye out next time I'm at the used cd shop.
Lucifer - I watched several of their videos and their music is very pleasant. I'll listen some more and pick up an album if the songs I hear are consistently good.
For anyone else skimming through this thread looking for nice vocals, I'll make my suggestions (many of which combine clean vocals with various metal styles):
-Opeth
-Orphaned Land
-Disillusion
-Borknagar
-Ulver
-Katatonia (later material)
-Unexpect
-Devin Townsend Band
-Riverside