Eric Clapton's pointless cover of I Shot The Sheriff that added nothing new at all, only robs the soul and meaning from the original.
Comparable to what Pat Boone did to black music back in the 50's.

Celion Dion & Anastasia (?) doing the cover of "You Shook Me All Night Long"

That happened..?

yes! lol. it's dreadful.

http://www.youtube.com/watch?v=ULmC8JTTVy0

their dancing doesn't help.

Don't Leave me this Way by the Communards. I only hate this version so much because I love the original so much (by Harold Melvin and the Blues Notes)

Wet Wet Wet singing Love is all Around (originally by the Troggs) on Top of the Pops was very awful as well

That's a wretched atrocity and he should be shot dead. Then stabbed in the face.

Really? I quite liked that. You can't go wrong with that mid-70s country rock sound round my house, you really can't.

I should note I could never tolerate the Buckley version.

I have a tough time with Song To The Siren in general for some reason.

it's quite a ok cover version, 70's all over the place but never really irritating.

I've neaver really liked that song or any of the more notorious covers of it myself. I mean, it's a good song, it just doesn't do it for me.

Metallica covering Thin Lizzy's cover of the traditional Irish folk song "Whiskey In The Jar". James Hetfield, you are not a Irish folk singer, so ixnay on the Gaelic lines. Then again, I'm betting he only knew the Thin Lizzy version and had no idea in was a folk song originally. Their cover of Killing Joke's "The Wait" is more respectable, but it's still not as cool as the original.

I like most of what Soundgarden's done, but I heard a live bootleg in which they covered the Beatles' "Come Together" and it was just awful. Sounded like beer commerical music.

That one too:
http://www.youtube.com/watch?v=EDw4bCx3icc

I'm surprised no one mentioned the best awful cover of all time:

Bono - Hallelujah
http://www.youtube.com/watch?v=LSwQX0Z5mHo

To be honest the original gets on my tits enough without Bono and you reminding me about it.

this isnt a cover version but it sounds like Noel Gallagher decided to try and cover a Guided By Voices song. Noel benefits from the assosciation