Here is a list of my favourite OSTs from dramas, movies, games or any form of media which can include an OST (e.g. CFs)!
100) Painful Hope - Lee Ki Chan (Dream High 2)
099) I Love You - Akdong Musician (Everything About My Relationship)
098) Just Say It - C-Real (Flower Boy Ramen Shop)
097) Tear Marks - Kim Jong Kook (Love in Memory 2)
096) The Way to Break Up - Kyuhyun (Poseidon)
095) That Woman - Baek Ji Young (Secret Garden)
094) GRAVitation - Secret (Tales Weaver)
093) Do It - Sunny Hill (I Love Italy)
092) Up & Down - EXID (Incarnation of Money)
091) My Heart is Moved - SeeYa (Personal Preference)
090) Always Missing You - Navi (Basketball)
089) The Little Match-Seller - Yoon Gun (History of a Salaryman)
088) Because It's You - Tiffany (Love Rain)
087) Love and Love - Baek Ji Young (Aarang and the Magistrate)
086) I Want to Go Back - Sojin (Passionate Love)
085) So Bitter - Lee Min Jung (Wonderful Radio)
084) Inoo - Kyuhyun (God of War)
083) Trail of Tears - Wheesung (Moon Embracing the Sun)
082) Farewell is Coming - Kang Min Kyung (Haeundae Lovers)
081) Because Tears Steal Hearts - Ailee (Secret)
080) It Has to Be You - Yesung (Cinderella's Sister)
079) To Live - Noel (Padam Padam)
078) Honey Honey - Girl's Day (The Woman of Our Home)
077) I Miss You - Yonghwa (You've Fallen For Me)
076) Empty - Hyun Jyu-ni (Iris)
075) Best Love - Lee Hyun (Fashion King)
074) Do You See - Shin Ji (Aftermath)
073) Let Us Just Love - A Pink (Protect the Boss)
072) Love of Iris - Shin Seung-hun (Iris)
071) Moonlight - Onew (Miss Korea)
070) Nung Cool Song - Girl's Day (My Husband Got A Family)
069) Love is You - K.Will (Aarang and the Magistrate)
068) Want to Go Back - Kim Bo Kyung (Secret)
067) Every Moment of You - Sung Si Kyung (You Who Came From the Stars)
066) Making Love - 4Minute (Personal Preference)
065) Think of It As A Dream - Gayoon (Poseidon)
064) I'll Protect You - Jaejoong (Protect the Boss)
063) Road of Tears - Changmin & Seulong (Time Slip Dr. Jin)
062) Because of You - Jea (History of a Salaryman)
061) Your Umbrella - Block B (The Thousandth Man)
060) If You're Like Me - Kim Hyun Joong (The Wedding Scheme)
059) Fantasy - Jang Jae In (Aarang and the Magistrate)
058) Promise - A.N.Jell (You're Beautiful)
057) I'm Loving You Today - Baek Ji Young (The Princess' Man)
056) Tears Fallin' Like Today - Huh Gak (You Who Came From the Stars)
055) Where Are You Now - Hello Venus (Afterschool Bokbulbok)
054) Stupid Love - J-Cera (Fermentation Family)
053) If - Taeyeon (Hong Gil Dong)
052) No - Yoseob (Poseidon)
051) Remember - U-Kiss (Syndrome)
050) Because It's You - Navi (Together Forever)
049) Living Like A Dream - Jaejoong (Time Slip Dr. Jin)
048) The Romantic - Two Months (The Romantic)
047) After A Long Time Has Passed - Baek Ji Young (Rooftop Prince)
046) Bye - Taeyeon (Mr. Go)
045) Thump Thump - Sunny Hill (The Greatest Love)
044) Be Alright - Yoseob & Gayoon & G.NA (Road For Hope)
043) Between Heaven And Hell - BoA (Shark)
042) Still - Lee Hong Ki (You're Beautiful)
041) Mariah - Kim Ah-Jung (200 Pounds Beauty)
040) Only One Who is You - Kim Soo Hyun (Moon Embracing the Sun)
039) Fool For You - Jea (Padam Padam)
038) It's Cold - Song Ji Eun (Take Care of Us, Captain)
037) Counting the Stars At Night - Sunny Hill (You're the Best Lee Soon Shin)
036) I Love You - Sunny Hill (Salamander Guru and the Gang)
035) Closer - Taeyeon (To the Beautiful You)
034) Hello To Myself - Ye Eun (Dream High 2)
033) Crazy of You - Hyorin (Master's Sun)
032) Bite My Lower Lips - eSNa (Heirs)
031) Stand Up - J-Min (To the Beautiful You)
030) Because It's You - Davichi (Big)
029) Can't Believe It - Younha (Personal Preference)
028) Don't You Know - Davichi (Iris 2)
027) Beautiful Days - J-Min (School 2013)
026) My Destiny - LYn (You Who Came From the Stars)
025) Snow Flower - Gummy (That Winter, The Wind Blows)
024) You Are So Beautiful - Junsu (Scent of a Woman)
023) And One - Taeyeon (That Winter, The Wind Blows)
022) A Person Like Tears - Changmin (Jeon Woo Chi)
021) Hurt - Ali (Rooftop Prince)
020) Heaven - Davichi (Gisaeng Ryeong)
019) Because It's You - Hyorin (Man of Honour)
018) Moonlight is Setting - Heora (Moon Embracing the Sun)
017) Incurable Disease - Navi (Secret)
016) Love Note - Ailee (Full House take 2)
015) Don't Forget Me - Baek Ji Young (Iris)
014) Page One - Soyeon & Ock Ju Hyun (Coffee House)
013) When the Sun Sets - Gavy NJ (Bridal Mask)
012) My Heart is Hit - Kim Bo Kyung (Two Weeks)
011) Back in Time - Lyn (Moon Embracing the Sun)
010) Missing You Like Crazy - Taeyeon (King 2 Hearts)
009) Black Paradise - B2ST (Iris 2)
008) Missing You - Navi (Come, Come, Absolutely Come)
007) Love is Like Snowflake - Junsu (Nice Guy)
006) Heart Road - Jessica (The King's Dream)
005) The End - Soyeon & Lee Boram (Gisaeng Ryeong)
004) Tell Me Now - G.NA (The Thousandth Man)
003) Don't Forget Me - Sohyang (Iris 2)
002) Just Once - Soyou (Empress Ki)
001) What Should We Finish - Soyeon (Death Bell 2)
Too many OSTs to list! Here's a few which didn't manage to make the list but are still good songs nevertheless!
Everything - Son Dambi (Light & Shadow)
Hero - J-Min (Miss Korea)
Little by Little - Jiyeon (Jungle Fish 2)
Let It Go - Hyorin (Frozen)
Maybe We - CSJH Dana (To the Beautiful You)
Dear My Family - SM Town (I AM)
Can You Hear Me - Taeyeon (Beethoven Virus)
A Goose's Dream - Insooni (Dream High)
Day After Day - Jiyeon (Dream High 2)
Dreaming - Kim Soo Hyun (Dream High)
