the first cover that comes to my mind is Paradise Lost's Mercy played by Orphaned Land (Israeli progrock band), somehow I like it much.. that eastern touch makes it more uplifting or so..
http://www.youtube.com/watch?v=tL7eX7C-65Eand speaking of Paradise Lost, I like their cover of Bronski Beat's Smalltown Boy
http://www.youtube.com/watch?v=f9XiD_2K7-Qand one that you'll probably find really bad, but I like it: Mnemic's Wild Boys (Duran Duran)
http://www.youtube.com/watch?v=0pDc0rVbmnYthere are also some tribute/cover albums I like, my favourite is The Lotus Eaters (Dead Can Dance tribute), then Love Like Blood: Chronology Of A Love Affair and Laibach's Jesus Christ Superstars (has covers for Lloyd Webber, Juno Reactor, Prince) plus their
other covers, e.g. for Status Quo:
http://www.youtube.com/watch?v=lZpGP6UN85Q