I'll go on record as saying Manson's "Sweet Dreams" not only doesn't hold a candle to the original, but actually put me off somewhat in my opinion of the band. When you take a nasty little song disguised by the upbeat New Wave sound and just play it nasty, you miss the point entirely. It's like explaining a joke. My view of "Tainted Love" is better, but the video was much more smart and funny than the cover. Again, having the boy assume a heartbroken girl stance on a song was new and fresh, with the added joy of the sinister Supremes cover tacked on at the end. Manson's goth gangsta bit would have worked better on something like George Michael's "Father Figure," Human League's "Don't You Want Me," or Psychadelic Fur's "Love My Way."
If "Tin Machine" is a pseudonym for John Lennon, I stand behind my opinion on "Working Class Hero". Otherwise, I've never heard of him/them, so I can't say. Faithful's voice is so much more worldly and weary than Lennon's, that's no contest in my book.
Not only is Nirvana's "The Man Who Sold the World" better than Bowie's, but Jake Dylan's band did a better job with "Heroes," and Mott The Hoople mops the floor with Bowie's laughably bad "All The Young Dudes." I find David Bowie to be a fascinating personality, but he's a lot cooler as an individual than he is as performer in most any arena. Both his singing and his acting can be sneezed at.
With "Sweet Jane," I'm talking about the original VU cut, since everything else is a revisitation.