Well, holy crap, another hard one. That's what she said? Oh goodness.
ANYWAY, I wish I could play a thousand instruments, but mostly, I wish I was really, really good at both the piano and the guitar. Like, really good. I'd been going back and forth between two different songs in this category, one for piano and (you guessed it) one for guitar. Both are impressive. Both are songs I wish I could play. However, I'm such a fan of this song (and this LIVE performance) that I had to go with Mr. Buckingham.
Man, I hope I rock like this when I'm his age. For REALZ.
(for those curious, this is the runner-up. but just the piano part.)