Will Arnett's Batman in The Lego Movie is a hilarious deconstruction of the modern incarnation of the character, a silly riff on not just Batman himself but the way he's seen by fans as infallible and awesome. Full of himself, sort of dumb, and the king of posturing, Arnett's Batman is actually endearing. He's my favorite take on the character since Michael Keaton.
And he has a song. And the song is awesome. Even better, it's got lyrics by Will Arnett (and directors Chris Miller and Phil Lord). DARKNESS! NO PARENTS!
Thanks to Dan Whitehead for pointing me to this video, which helpfully includes the lyrics, in case you couldn't understand them (for some terrible reason).