I suppose you can check out Kataklysm. Their older stuff is heavy as fuck with chaotic structures and a vocalist with a really, really good range (I'm talking demonic growls and higher-than black shrieks). Their stuff post-Temple is more melodic driven, but keeps the heaviness. The vocalist has a nice range, but not as great as Houde. If you want truly devastating stuff, go for their older stuff (Pre-Victims), but their newer stuff is pretty good too.
And i'll second Vader, for that matter. Also, I think you'd like Laethora too.