What's your favorite soundtrack songs?
I'm not sure if Chinese include Taiwanese but as always, i fav Taiwanese dramas are Autumn concerto and Fated to love you. They have amazing ost songs but the ones that i like best are I Love Him/Wo Ai Ta from Della Ding (Autumn concerto) and My happiness/Wo De Kuai Le - Jin Xiu Er Chong Chang (Fated to love you). They're are so sad yet are too good!
From Chinese dramas I really like Lan Ling Wang ost especially : Heart of palms [/URL] By Della Ding , Ming Yun By Jia Jia , Feng Kuang De Cun Zai By Richie Chen and all the instrumentals *0*
+ I Really like Plum Blossoms in heaven and earth ( Vigilantes in Masks ) .

For Taïwanese dramas I prefer My lucky star ost ( such a masterpiece *0* )
From ISWAK I'm still in love with Say U love Me <3 .
I did not watch Bull Fighting but I Love Dou niu yao bu yao by Tank & Trapped beast by Judy Zhou *0*
Black & White : Rogue Justice and the other songs .
All the soudtrack from Mars .

[U]Chou Nan Ren
~Huang YiDa ( eheh my favorite asian singer <3) ( DBY)
Why Why Love : The world I want & Wan mei bi li ~Rainie Yang . etc .

There others but I think that is too much , sorry . And I agree with Se-Kyung0209 Wo Ai Ta from Della Ding is so awesome and also All for love by Victor Wang *0* .
Small part of my list ^~^

Why Did You Lie - Della Ding (Autumn's Concerto)
I Love Him - Della Ding (Autumn's Concerto)
One Kiss, Barren Sky - Hu Ge (Xuan Yuan Sword - Rift of the Sky)
Three Inches of Heaven - Yan Yi Dan (Bu Bu Jing Xin)
Sad Fairytale - Hu Xia (Sad Fairytale)
Wish I Loved You Less - Andrew (Holy Pearl)
Insist on Love - Zhang Yun Jing (Chinese Paladin 3)
Promise I Won't Love You - Ronald Cheng (Chinese Paladin 3)
Destiny - Jia Jia (Lan Ling Wang / Prince of Lan Ling)
Heart of Palms - Della Ding (Lan Ling Wang / Prince of Lan Ling)
In the Middle - Jasmine Leong (Love Contract)
Very Beautiful - Lv Wen (Love Waking Up)
Love Does Not Travel Alone - Show Luo (Hi, My Sweetheart)
There is a Kind of Love Called Letting Go - Ah Mu (Love in the Forlorn City)
Ai De Gong Yang - Yang Mi (Gong)
Goldfish's Tears - Ji Jia Song (Queen of SOP)
Being the Friend Who Loves You Most - Zhang Han (Queen of SOP)
I Won't Love You - Bolin Chen (In Time With You)
the soundtrack to Inborn Pair, Fated to Love You, Autumn's Concerto, Devil Beside You.
I just wanted to add this song Nicholas Tse feat. Charlene Choi - Sacred Love (情聖). It's from the Chinese movie A Chinese Tall Story, it's silly, but the song is great!
My favourite songs:

Black & White – all songs, hard to choose just one!
Happy & Love Forever: Jam Hsiao - Wish You Happiness
Silence: Vic Zhou - Shou Xi De Wen Rou
Chinese Paladin 3: Zhang Yun Jing - Pian Ai
Sophie's Revenge: Angela Zhang & Harlem Yu - Very Perfect
Summer's Desire: Barbie Xu - Zuan Shi
Da Ren Wu: Zhang Yao, Ma Shang Yo – Moonlight
Unbeatable II: Craze - Don't Answer
Mars: Alan Kuo - Ling
Channel X: Anthony Neely - Happy Doomsday
Jade Palace Lock Heart: Mickey He - Jian Huo Bu Jian
Devil Beside You: Rainie Yang - Ai Mei
Love, Now: Yen-J - Add Fuel to Fire
Swordsman: Wallace Huo – Carefree
Strange Hero Yi Zhi Mei: Hu Ge - Plum Blossoms in Heaven and Earth
Bii - Come back to me (from the taiwanese drama Love Around) ^^
I really loved the OSTs from Lanling Wang and Bu Bu Jing Xin :) (both really great dramas as well)
can anyone help me find the ost of this movie Sweet Summer Love
There are just so many! 

Taiwanese Dramas
终极一班 (KO One):
终极一家 (The X-Family):
  • 够爱 - 东城卫 & 谢和弦A.Chord
终极一班2 (KO One Returns):
终极一班3 (KO One Re-act):
终极X宿舍 (The X-Dormitory):
终极恶女 (Angel N Devil):
恶作剧之吻 (It Started With A Kiss):
命中注定我爱你 (Fated To Love You):
  • 越唱越大声 - 叶怀佩 (春梅HARU OST)(in Taiwanese dialect)
  • 印记 - 林雨宣 (顶坡角上的家 Home Away From Home OST)(in Taiwanese dialect)
  • 全世界都停电 - Tank (爱就宅一起 ToGetHer OST)
  • 一个人就好 - 刘力扬 Jade Liu (爱就宅一起 ToGetHer OST)
  • 默默 - 飞轮海Fahrenheit (爱就宅一起 ToGetHer OST)
  • 没有如果 - 梁静茹 Fish Leong (败犬女王 My Queen OST)
  • 无赖正义 - COLOR乐团 (痞子英雄 Black and White OST)
  • 我是谁 我是谁 我是谁 - 魔幻力量Magic Power (偷心大圣PS男 PS Man OST)
  • 情非得已 - 庾澄庆 Harlem Yu (流星花园 Meteor Garden OST)
  • 绝不能失去你 - F4 (流星花园II Meteor Garden II)
  • 爱一直存在 - 梁文音 Rachel Liang (紫玫瑰 Roseate Love OST)
  • 带我走 - 杨丞琳 Rainie Yang (不良笑花 Miss No Good OST)
  • 来不及 - 田馥甄 Hebe Tian (斗牛要不要 Bull Fighting OST)
  • 背影 - 林宥嘉 Yoga Lin (斗牛要不要 Bull Fighting OST)
  • 叶子 - 阿桑 (蔷薇之恋 OST)
  • 猜不透 - 丁噹 (幸福的抉择 I Do? OST)
Mainland Chinese Dramas
  • 不悔 - 陆昱霖 & 刘庭羽 (后宫 The Emperor's Harem OST)
  • 三寸天堂 - 严艺丹 (步步惊心 Scarlet Heart OST)
  • 尘埃 - 家家 Jia Jia (步步惊情 Scarelt Heart 2 OST)
  • - 动力火车 Power Station (还珠格格 Princess Returning Pearl)
  • 忘了算了 - 范怡文 (活佛济公 The Legend of the Crazy Monk OST)
  • 黄种人 - 谢霆锋 Nicholas Tse (小鱼儿与花无缺 The Invincible Duo OST)

There are more like from movies but I'll just stop here...
A nobody and a princess - Ian Chen
Unstoppable Sun- Aaron Yan