If you're looking for some sick Sabbath coversLook no further...
Buy the Nativity in Black set...
Here's the track listing for each CD...
CD 1 - A Tribute to Black Sabbath: Nativity in Black 
1. After Forever [Biohazard]
2. Children of the Grave [White Zombie]
3. Paranoid [MegaDeth]
4. Supernaut [1000 Homo DJs]
5. Iron Man [Ozzy with Therapy?]
6. Lord of This World [Corrosion of Conformity]
7. Symptom of the Universe [Sepultura]
8. The Wizard [Bullring Brummies (featuring Geezer Butler, Bill Ward, and Rob Halford)]
9. Sabbath, Bloody Sabbath [Bruce Dickinson with Godspeed]
10. NIB [Ugly Kid Joe]
11. War Pigs [Faith No More]
12. Black Sabbath [Type O Negative]
13. Solitude [Cathedral]
CD 2 - A Tribute to Black Sabbath: Nativity in Black II 
1. Sweet Leaf [Godsmack]
2. Hole in the Sky [Machine Head]
3. Behind the Wall of Sleep [Static-X]
4. Never Say Die [MegaDeth]
5. Snowblind [System of a Down]
6. Electric Funeral [Pantera]
7. NIB [Ozzy Osbourne with Primus]
8. Hand of Doom [Slayer]
9. Under the Sun [Soulfly]
10. Sabbra Cadabra [hed (PE)]
11. Into the Void [Monster Magnet]
12. Iron Man [Busta Rhymes]
These covers are extremely well done as every artist made it their own. The only one I don't appreciate is Busta Rhyme's Iron Man, because it's rap......but everything else is metal!
The other thing I'm upset about is that Iced Earth's cover of Electric Funeral didn't make it. Though, Pantera's version is fucking awesome as well.
And those that are upset that IE's version of Black Sabbath didn't make it, it wasn't recorded in time.
Being the doomite that I am I have both of these and a few more Sabbath Tributes. Some are great, some are just downright boring and probably good for some temporary laughs.
Each discography for the tributes can be found at Black Sabbath's Discography. Scroll down to see a listing of all the tributes.