Mine is Brenda Lee. I listen to mostly rock music everyday, but whenever it’s time for bed, it’s Brenda Lee for me and no one else. Her songs help me fall asleep earlier than usual.
So what kind of music do you play to help you fall asleep faster? 
At the end of the day (ha), I find that silence is best for sleep. But I do have a mix of Sufjan Stevens and the Fog of War stk for drifting off.
That’s funny cause I just had to get a Fisher-Price Waterfall set for myself to get to sleep to. It can play jungle music and lullabies and you can watch the little animals peeping in and out in the peaceful jungle waterfall! It was in the $12 price rack but it rang up at $35 and I said no way.
But then I had to go back for it because I fell in love with its tranquility and soothing jungle sounds.
Don’t tell anyone 
My Yahoo Music (8,675 selections) playing on full random all night, every night. Can’t sleep without it.
Cocteau Twins - Victorialand - lush ambient soundscapes inspired by a documentary on Antarctica. Works on my 2 y.o., works on me.
No music, but since it fits your question in a general way… I put on Old-Time Radio shows. I find that the voices lull me to sleep better than music for some reason. Not to say that they’re boring and knock you out, I’m a huge fan of OTR, actually.
Sir Rhosis
Jim Brickman’s piano pieces.
The local NPR affiliate on FM has a dynamite classical FM station, you know the type with the announcer intoning “…arranged for marimba, bass, and guitar…” (Whatever happened to Peter VanDegraff??) and they usually do a pretty good job of slumber-type classical, nothing too rousing or boisterous to interfere with the various humers and night-time phlogistin.
The KLF: Chill Out
has to be heard. It put’s me to sleep before I can get to the end of it. Very relaxing. It’s like a soundscape of outdoor country noises (crickets, trains, distant cars, a radio playing in the background).
For a better explanation read some of the reviews here
It was really funny last year when my roommate and I went and saw Dead Can Dance live. About 20 minutes into the concert, she started to get really tired and realized that it was because DCD was her bedtime music.
For me, it’s usually Mazzy Star - I just love her voice, and there’s something about the pacing of the music that really chills me out. Also PJ Harvey’s “Is This Desire” or “Under the Pink” by Tori Amos. I’m so predictable and repetitive with those three CDs that I have to be really careful about what music I pack for a car trip - like <b>interface2x</b> said, the association is strong. After thirty seconds of “Pretty Good Year” I’m rolling down the window to keep myself awake.
Aww, crap. My second post and I’ve already made a coding mistake! Apologies, all.
Ah, I want this! Also, a friend lent me a a track that played ocean sounds. The occasional seagull shrieks kept waking me up! 