Covered Up - While not completely overshadowing the original, their cover of Gary Numan's "Cars" is usually the one that appears most in commercials and other media. Perhaps subverted, considering Gary Numan does the vocals on the cover, but still. They've pretty much completely covered up "Dog Day Sunrise" (originally by Head of David) and "0~0" (originally by Wiseblood), though.
Misattributed Song - They never did a cover of Kiss' "God of Thunder", that was by Death.
Doesn't it count as a subversion since the drummer for Death later drummed for Fear Factory?
Nightmare Fuel - The song 'Slave Labor' is about self-immolation, which means burning yourself alive.