Smashing Pumpkins' We Only Come Out At Night has always been my Milliways theme song. I mean, lyrics:

We only come out at night, the days are much too bright
We only come out at night
And once again, you'll pretend to know me well, my friends
And once again, I'll pretend to know the way
Thru the empty space
Thru the secret places of the heart
We only come out at night, the days are much too bright
We only come out at night
I walk alone, I walk alone to find the way home
I'm on my own, I'm on my own to see the ways
That I can't help the days, you will make it home o.k.
I know you can, and you can
We only come out at night, the days are much too bright
We only come out at night
And once again, you'll pretend to know that
There's an end, that there's an end to this begin
It will help you sleep at night
It will make it seem that right is always right
Alright?
We only come out at night

There's the original version, or this cover by Fanfarlo that I actually think I'm liking better at the moment. (Except for the voice thing. No one can touch Billy Corgan's voice.)