Wow, that's weird. I was watching football and on one of the commercials was some hipster band - sounded a little rockabilly/punkish - doing a cover of "My Way" by Sinatra (well, Paul Anka, really) and I was like "God, I'm so OVER the ironic cover of classic songs by smart-asses that don't get it", and then this thread.
I'm really weird when it comes to covers. I love the song "Baker Street", I like the Foo Fighters, but I hate their version of it. To my mind, misses the essence of the song. I dig Ugly Kid Joe's "Cat's Cradle". I'm in on almost every one of Cheap Trick's Beatles covers. I'm in on almost all of Oasis' covers (Heroes, Street Fightin' Man, You've Got To Hide Your Love Away, I Am The Walrus...).
There's a fine line there.