I think it depends on whoever is redoing it and what the song is. Some people completely mess up songs, while some put it to justice. Can't think of any goth examples here, but here's a non-goth one anyways...the Relient K (yes, you may cringe) version of "We Are The Pirates Who Don't Do Anything" can NEVER compare to the brilliancy of the original VeggieTales (yes, you may cringe, but I love the show all the same since I'm religious and it's funny) version. But I like Marilyn Manson's version of "Sweet Dreams". I don't know why, but I do.

I am a big fan of cover versions and have a few albums of "tribute" albums based around Goth bands.

I love the Mission's version of Atomic (which can be found on the NME "Ruby Trax" album) and I really like Minstry's version of "What a Wonderful World".

Nouvelle Vague have done some awesome Goth, Punk and Two Tone covers. Their version of Lords of the New Church's "Dance with Me" is inspired.

Not the worst cover I've heard but possibly the creepiest is Lords of the New Church covering "Like a Virgin"... (makes me want to shower afterwards, it just makes you feel dirty) :D

Rosetta Stone do a good version of "Venus in Furs" and "The Witch" is one of their more famous songs.

I even have a live version of SoM singing the Kylie Minogue song "Confide in Me" which isn't bad either.

i feel that a band called Van Canto does amazing covers of music i don't normally listen to like metallica.
but glee is one cover band i despise