The best covers you've ever heard ..

Nevermore - The Sound Of Silence
Type O Negative - Paranoid
Type O Negative - Black Sabbath
Megadeth - Paranoid
At the Gates - (no idea what it's called, but I have an mp3 called legion which is absolutely wicked...)
Devin Townsend/SYL - Far beyond METAAAAAAAAAALLLLL!!!!!!!!!
Xentrix - Ghostbusters
 
Nevermore - Sound of Silence
Tool - No Quarter

And I know this doesnt count, but a band that I was in back in the day used to do Gwar's "have you seen me". Talk about fucking funny....
 
ALL NEVERMORE/SANCTUARY, DEATH, PANTERA, ZAKK WYLDE/B.L.S, ANTHRAX, TOOL, SACRED REICH, MEGADETH, DEATH ANGEL/ORGANIZATION AND MOST OF METALLICA'S COVERS ARE GOOD. There are "hit and miss" meaning good/bad covers on the N.I.B. TRIBUTES VOL. 1&2, PRIEST TRIBUTES VOL. 1&2, AND THE KISS MY ASS KISS TRIBUTE.