Try 90's Brutal Truth.

I'm looking for something similar to Mastodon's Crack the Skye (stop laughing and dont say Leviathan), which after 6 months I cant stop listening to.

Have you explored the rest of their discography?

Edit: I can't really think of anything that similar. The vocals are pretty distinct, and I think that alone makes the sound not so generic.

Yeah, that's the problem. I love their discography, but I'm looking for something conceptually similar to CtS, plus I really love the vocals on the album.

Ah, I see. You're seeking concept albums as well. When you say conceptually similar, do you mean Greek Mythology? Hinds and Sanders are amazing vocalists and I've not found anything as unique as them.

An album with a very cohesive sound. Not simply a collection of songs.

We shall hunt for it together!

You listen to Between the Buried and Me any?

No, but I will. as an aside something about mastodon's vocals reminds me a bit of Alice in Chains Dirt era. Do you get that?

Yes, I was actually going to mention AiC, but figured it'd be irrelevant because none of their newer stuff is similar. At least I don't think so. If you get into Between the Buried and Me, start out with Alaska. I'm biased, so talked to other BTBAM listeners, too, but I'm not too fond of anything before that. Antonio is pretty knowledgeable on them. They are way heavier in the vocals than Mastodon, but there are also distinct similarities. The reason I say start with Alaska because I want you to experience the transition to Colors and to their latest The Great Misdirect. I've not fully listen to the new album, but have already decided that it's in the shadows of Colors. If you need links, I'll be on later to up some stuff for you. Hope I helped!

Hmmm....High on Fire!!!!