Here's another sign that Nirvana's "Smells Like Teen Spirit" is now a classic. Not only is the baby on the cover now 17 years old, but the tune has also been covered by crooner Paul Anka (on his 2005 Rock Swings album, apparently). I defy you not to get this catchy version stuck in your head: "Nirvana. Yes, Nirvana! Come on!""