Not too growly, not too clean?

Yeah, Ripper is not my kind of singer. I cringe when he hits the high notes...lol

Although I do enjoy listening to some high pitched singers. Nils Rue from Pagan's Mind has a high pitch and I think he's great. Of course he doesn't hit the high pitches all the time.
 
Strike first records (facedown records) just release a band called "Hope for the Dying" you might like them. Some singing/some screaming, but no "death" style screaming that I've heard on their myspace.
 
Primordial
Venom
Devin Townsend
Soilwork
Mnemic
maybe some of Agalloch
and some of Sturmgeist
 
The only Agalloch I have is Ashes Against The Grain. It's great. Not too much singing, just a lot of very hypnotic whatever it is. Third wave neofolk or something. I don't care. It's great. The Mantle, The White EP, and Pale Folklore are supposed to be even better, and I'll definitely be picking them up.