Songs you can't get out of your head..
 

Kylie - Can't get you outta my head (very appropriate isn't it? LOL)
KinKi Kids - solitude~shinjitsu no sayonara~
KinKi Kids*Koichi Domoto - Tsuki no monogatari
KinKi Kids*Tsuyoshi Domoto - Hitori Janai
Ayu - Moments, A Song For XX
D.A.I - fukai mori, buranko, shinjitsu no uta
Namie - Put em' up
Tackey & Tsubasa - Yume monogatari
Tackey - Kaze no uta
Willy Hung - She Bangs! (LOL)
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Duhzzz so many... haha suminmasen...

WINDING ROAD-BoA feat. DABO--> Stuck in my head all day.
Kokoro no tegami-BoA-->Plays in my head everyday.
No way to say-Ayumi Hamasaki
Fukai Mori-D.A.I

Crystal Kay - Boyfriend -part II-
Crystal Kay - Can't be Stopped
Crystal Kay loves M-FLO - I like it
tamaki nami - Believe
tamaki nami - Shining Star *Wasurenaikara*

Every Ayu song that has a ~lalalalala~ in it.
Eg: Moments. Agh!!!

amuro namie - alarm
kokia - track3 in her single "so much love for you" [surprisingly XP]
jay-z - dirt off your shoulder

songs i can't get out of my head changes all the time, but some that has happened in the past include

Ayu- ANGEL'S SONG
Nami Tamaki- Believe
Every Little Thing- Fundamental Love (esp Ichiro's guitars)
Shiina Ringo- Mayonaka wa junketsu

ayumi - a song for xx

Depends on what music I'm into at the time, but here are some songs that pop into my head even though I haven't been listening to em lately

~Ayumi Hamasaki - Voyage (Ayu Trance version)
~Utada Hikaru - Kettobase!
~Namie Amuro - I WILL
~Aya Matsuura - Goodbye Natsuo ~Wild Ayaya Version~
~Ayumi Hamasaki - M (Above and Beyond remix)
~BoA - Be the One
~Gackt - 4th
~Gackt - Jyuu ni gatsu Love Song
~Malice Mizer - Le Ciel

Ayumi Hamasaki - Rainbow

I don't even know why I get it stuck in my head so often!! Probably cause it's got a repetitive melody..

I also get a lot of OLIVIA songs stuck in my head cause they're very repetitive...

D12 - 40 oz

oh...and w-inds. - Long Road o_O"

Mika Nakashima - STARS
Shiina Ringo - Koko de kisu shite

Ayu-Real Me,It seems like that song always gets stuck in my head...lol

i get seasons, never ever and BoA's korean verion of NO.1

Ayu's Dearest. I dunno why but i ALWAYS have this song in my head. If I dont, I have Aiko's Chouchou Musubi (very catchy song). I haven't noticed this thread before today... strange. I was almost sure I posted in it! lol

That's what I thought of too... and it's true, it's stuck in my head now :)

Ayu - No way to say
Linkin Park - papercut
Kagrra - haru urara
Dir en grey - Increase Blue

Oh yeah I forgot Noir Fleurir - Omocha no Miisha
"boku no miisha...."

at the moment:

blame / music takes you

Ayu - Naturally
Namie - Alarm
Christina Millian - Dip it low
Chingy - One Call Away
As One - Mr. AJo