The Flaming Lips do a great Bohemian Rhapsody, but it is not better than the original.
I recall The Flaming Lips covering a Kylie song on a TV show, once. They turned it into a rare old slice of weirdness. Hehehehe.
And on the same show, Elbow covered a Sabbath song - I don't remember which song it was (The Wizard, maybe? ...I dunno), but they did an incredible job.