Ray Alder of Fates Warning (especially their last few albums).
Lars Eikind, who plays bass and provides the clean vocals in Before the Dawn
and it's sister project Dawn of Solace
(Finish metal band).
I'm really digging the vocals on Katatonia,
although he doesn't exactly have the best range, he's very effective with what he can do.
And of my favorite singers, Devon Graves of Dead Soul Tribe has a new band, Shadow Theory: http://www.myspace.com/theshadowtheoryofficial