There was a long thread about this on the old board. Here is a site with lots of info. on cover songs:
http://www.coversproject.com/
I prefer cover songs that sound nothing like the original. What point is there in playing a song note-for-note? I want to hear a new interpretation.
Some covers surpass the original, or sound completely different. Ex. Jimi Hendrix covering Dylan's "All Along the Watchtower", or Derek & the Dominoes doing Hendrix's "Little Wing".