There's an obscene range in the quality of various covers that have been recorded. Some could suck a golf ball through a garden hose. (See Marilyn Manson's cover of the Eurythmics' "Sweet Dreams.") Some are pretty good. Metallica's cover of Whiskey in the Jar, and James Hetfield's cover of "Don't You Think This Outlaw Bit's Done Got Out of Hand" both come to mind. Some covers actually improve on the original, like Uncle Kracker covering "Time After Time." (Seriously, go find it. Well worth the time it takes to look.)
And sometimes a cover blows the doors clean off the original. This is unquestionably the case with Seether's cover of "Careless Whisper."
Sorry there's no actual video this week, this is the best I could find. Seriously, I don't think I've heard Seether do anything I don't like, and this one I happen to love.