Like I mentioned Brainoil comes to mind, but when it comes to their guitar tone the only other band I can think of is Blessing The Hogs. It's a sound that's definitely more in line with other forms of Extreme Metal than your typical Stoner Doom or Sludge. Feedback is strewn between riffs and helps with creating a misanthropic atmosphere. The bass although it's hard to pinpoint sometimes in the mix, is most definitely there and it's distorted as fuck and fits right in with the overall nastiness of the band. The vocals are fantastic with its shrieking cries of hate and misery. There's also a lower death growl vocal that's employed at various times for great effect. Going along with the whole Extreme Metal vibe, the drummer seems to be avoiding the regular Stoner Doom or Sludge tendencies of just playing slow, and is pretty varied making use of interesting fills as well as decent foot work on the double kick.
I highly recommend this tasty sliver of rage inducing sludge. My only complaint is that this release is only 3 songs, and they're kinda short, so I'm definitely anticipating more! If you like your Sludge Doom being a few shades away from just being straight up Death Metal then this shit is probably for you. Great stuff! Cheers! -Samir