Muse Streets and Johnny Cash One are both awesome, I think.
John Legend did Pride on piano, and I really liked that.
The Chili Peppers sometimes do a good 2 minutes of SBS after a drum solo, they always sound pretty good to my ears.
I know there have been plenty of butchered covers, but overall, I think many artists know how to respect U2 without trying to copy them. Almost everyone knows it is extremely difficult to reproduce their sound, so they vary it a bit.
I have even found some pretty good amateur covers on Youtube, and my friend from college who is a huge DMB fan and a casual U2 fan would often do pretty damn good acoustic and electric versions of One, Still Haven't Found, Pride, I Will Follow and In God's Country to name a few.
I have seen the Joshua Tree, a Boston based U2 tribute band 3 times now, and damn, do those guys hit every song spot on! But they are a real anomaly as far as tributes go, I think. They have been at it a long time, all do it for their full time jobs, and they work their asses off. Zoo Tv WOWY solo, Shine Like Stars, Hear us Coming, snippets in Bad, etc, so much of what U2 does in their own shows is incorporated perfectly by this band. I have written up a few reviews of them in the appropriate section of the forum, I explain in detail how much studying and film watching these guys must do. It would put the College Football Coach to shame!
I would never buy the argument that "U2 covers are the exact same, they're the real thing or even better
and you don't have to see the real band, they're so easy for any beer league band to reproduce."
But I certainly don't buy the argument that all people ever do is butcher their songs.