I always listening these song lately :
Super Junior K.R.Y - earthquake,
T-ara, Davichi - We were in Love
Super Junior - Way
Ryeowook - Sungmin duet - Story
Hyorin (Sistar) - I choose to love you
Super Junior -A Short Journey
super junior T - there is no one
TaeYeon & The One - Like A Star

OMG SOOOO MANY!!!!! but here's a few that I really love :)

I Confess - FT Island
Crying - Heo YoungSaeng
Its all lies - BAP
Nalina -Block B
Nu Abo - F(x)
Stay - Ft Island
When the door closes - B2ST
Ugly - 2NE1
Man Man Ha Ni - UKiss
I Miss You - Noel
Stupid Liar - Big Bang
Love Song - Big Bang
Electricity - 2PM
You & I - Boyfriend
0330 - UKISS
Baby dont Cry - Daesung
You Are So Beautiful - Junsu (JYJ)
I'll Protect You - Jaejoong (Protect the Boss OST)
Uncertain Love - Horan (Clazziquai)
In Life and Death - Wheesung

SHINEE ~
Love Pain
Jojo
Kiss Kiss Kiss (jap)
Obsession
Romantic
Y.O.U.
Please, Dont Go

TVXQ ~
Mirotic
Hug
Insa
Before You Go
Dou____e (jap)
How Can I

SUPER JUNIOR ~
Walkin'
No Other
Neorago
Coagulation
My Everything (Donghae)
Late Autumn (Kyu)
My Love My Kiss My HeartWhy I Like You
ugh... who am I kidding I love ALL SuJu songs!!! >>____<< LOL

WOW dat was long o.O soweee

never again - SS501
is you - ryu duk hwan
i think i love you - byul
lucky - ashily
starlight tears - kim yu kyung
to her - 2AM ft chansung 2pm
my man - davinchi
if you come into my heart - mblaq ft C-luv
time to walk memories - nell
one last cry - N-train
sad song - baek ah yeon
one more day - chocolat (i really like this song^^)

hope this will help^^

time to love - supernova t-ara
cry cry - T-ara
it has to be you - Yesung (cinderella step sister OST)
la vida loca - clover
run to you -Dj Doc
run - epic high
my destiny - dongbangshinki
tonight - dongbangshinki
fiction - beast
run devil run - snsd
monalisa - mblaq
before the dawn - infinate
go away - 2ne1
you and I - Park bom
tell me goodbye - bigbang

superjunior
superman
super girl
good man
no other
for u
shining star

Sky High - CN Blue
Love Light - CN Blue
Wanna Do - Kara Jiyoung
Mirotic - TVXQ
Bittersweet - Super Junior
Daydream - Super Junior
Blue Tomorrow - Super Junior M
Close Your Mouth - M&D
Stand Up - J-Min
Magnet - EvoL
Fool - Juniel Ft. Yonghwa
Illa Illa - Juniel
Hot - 2PM
Put Your Hands Up - 2PM
Back In Time - LyN

That's all for now~^^

Loving you-SJ KRY
Let's Not-SJ KRY
Fool-Juniel ft. CN Blue Younghwa
Beautiful-Beast
Forget me now-gummy
So I-SJ
Happy together-SJ
Your Eyes-SJ Yesung and Kyuhyun
Sunflower-SJ
Angel-SJ
I Do-SJ Yesung
If you love me more- SJ Ryeowook
Love of seven years-SJ kyuhyun
Daydream-SJ
Cry-Mblaq
Loving you-So Eun Lee
Love is Sweet-SJ M
Always be Mine-FT Island
In my dream-SJ
Bittersweet-SJ
From U-SJ
You and I-SJ Happy
Love U more-SJ
Only U-SJ
I think I love you-Byul
Dropping rain-Kim tae woo

Plz Don't - Donghae
Loving You - KRY
Err...
Se7en - Come Back To Me
Se7en - Better Together
MBLAQ - Mona Lisa

There's one by Heechul, I can't remember what it's called, but it's one of my favourites. ;)